Grzimek's SALR - Reptiles
Grzimek's SALR - Reptiles
Grzimek's SALR - Reptiles
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Mertz, Leslie A.
Grzimek’s student animal life resource. Reptiles / Leslie A. Mertz ; edited by Neil
Schlager and Jayne Weisblatt.
p. cm.
Includes bibliographical references and index.
ISBN 0-7876-9404-5 (hardcover set : alk. paper) — ISBN 0-7876-9405-3 (volume
1) — ISBN 0-7876-9406-1 (volume 2)
1. Reptiles—Juvenile literature. I. Schlager, Neil, 1966- II. Weisblatt, Jayne. III.
Title.
QL644.2.M427 2005
597.9—dc22 2005000033
ISBN 0-7876-9402-9 (21-vol set), ISBN 0-7876-9404-5 (2-vol set), ISBN 0-7876-9405-3 (vol 1), ISBN 0-7876-9406-1 (vol 2)
Printed in Canada
10 9 8 7 6 5 4 3 2 1
Contents
REPTILES: VOLUME 1
Readers Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ix
Pronunciation Guide for Scientific Names . . . . . . . . . . . .xi
Words to Know . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xvii
Getting to Know Reptiles . . . . . . . . . . . . . . . . . . . . .xxvii
Dinosaurs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Tuatara . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132
Contents v
Snakes and lizards . . . . . . . . . . . . . . . . . . . . . . .139
Angleheads, calotes, dragon lizards, and relatives . . . . . .145
Chameleons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156
Anoles, iguanas, and relatives . . . . . . . . . . . . . . . . . . . .167
Geckos and pygopods . . . . . . . . . . . . . . . . . . . . . . . . . .177
Blindskinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186
Wormlizards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .190
Mole-limbed wormlizards . . . . . . . . . . . . . . . . . . . . . . .197
Florida wormlizard . . . . . . . . . . . . . . . . . . . . . . . . . . . .203
Spade-headed wormlizards . . . . . . . . . . . . . . . . . . . . . . .208
Species List by Biome . . . . . . . . . . . . . . . . . . . . . . . . .xli
Species List by Geographic Range . . . . . . . . . . . . . . . .xliii
Index . . . . . . . . . . . . . . . . . . . see the Cumulative Index
REPTILES: VOLUME 2
Readers Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ix
Pronunciation Guide for Scientific Names . . . . . . . . . . . .xi
Words to Know . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xvii
Getting to Know Reptiles . . . . . . . . . . . . . . . . . . . . .xxvii
Night lizards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .215
Wall lizards, rock lizards, and relatives . . . . . . . . . . . . . .221
Microteiids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .228
Whiptail lizards, tegus, and relatives . . . . . . . . . . . . . . .235
Girdled and plated lizards . . . . . . . . . . . . . . . . . . . . . . .243
Skinks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .249
Alligator lizards, galliwasps, and relatives . . . . . . . . . . . . .260
Knob-scaled lizards . . . . . . . . . . . . . . . . . . . . . . . . . . . .267
Gila monster and Mexican beaded lizard . . . . . . . . . . . .273
Monitors, goannas, and earless monitor . . . . . . . . . . . . .279
Early blind snakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .288
Slender blind snakes, thread snakes, or worm snakes . . .295
Blind snakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .302
False blind snakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .309
Shieldtail snakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .314
Pipe snakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .320
False coral snake . . . . . . . . . . . . . . . . . . . . . . . . . . . . .326
Sunbeam snakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .331
Neotropical sunbeam snake . . . . . . . . . . . . . . . . . . . . . .337
Boas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .342
Pythons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .353
Splitjaw snake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .363
Woodsnakes and spinejaw snakes . . . . . . . . . . . . . . . . .369
File snakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .375
Vipers and pitvipers . . . . . . . . . . . . . . . . . . . . . . . . . . .380
African burrowing snakes . . . . . . . . . . . . . . . . . . . . . . .393
Colubrids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .399
Contents vii
Reader’s Guide
Grzimek’s Student Animal Life Resource: Reptiles offers read-
ers comprehensive and easy-to-use information on Earth’s rep-
tiles. Order entries provide an overview of a group of families,
and family entries provide an overview of a particular family.
Entries are arranged by taxonomy, the science through which
living things are classified into related groups. Each entry in-
cludes sections on physical characteristics; geographic range;
habitat; diet; behavior and reproduction; animals and people;
and conservation status. All entries are followed by one or more
species accounts with the same information as well as a range
map and photo or illustration for each species. Entries conclude
with a list of books, periodicals, and Web sites that may be used
for further research.
ADDITIONAL FEATURES
Each volume of Grzimek’s Student Animal Life Resource: Rep-
tiles includes a pronunciation guide for scientific names, a glos-
sary, an overview of Reptiles, a list of species in the set by
biome, a list of species by geographic range, and an index. The
set has 180 full-color maps, photos, and illustrations to enliven
the text, and sidebars provide additional facts and related in-
formation.
NOTE
Grzimek’s Student Animal Life Resource: Reptiles has standard-
ized information in the Conservation Status section. The IUCN
Red List provides the world’s most comprehensive inventory of
Reader’s Guide ix
the global conservation status of plants and animals. Using a set
of criteria to evaluate extinction risk, the IUCN recognizes the
following categories: Extinct, Extinct in the Wild, Critically En-
dangered, Endangered, Vulnerable, Conservation Dependent,
Near Threatened, Least Concern, and Data Deficient. These terms
are defined where they are used in the text, but for a complete
explanation of each category, visit the IUCN web page at http://
www.iucn.org/themes/ssc/redlists/RLcats2001booklet.html.
ACKNOWLEDGEMENTS
Gale would like to thank several individuals for their assis-
tance with this set. Leslie Mertz wrote the vast majority of the
text; Linda Patricia Kite also wrote a few articles. At Schlager
Group Inc., Neil Schlager and Jayne Weisblatt coordinated the
writing and editing of the set, while Marcia Merryman Means
and Leah Tieger also provided valuable assistance.
Special thanks are also due for the invaluable comments and
suggestions provided by the Grzimek’s Student Animal Life Re-
source: Reptiles advisors:
• Mary Alice Anderson, Media Specialist, Winona Middle
School, Winona, Minnesota
• Thane Johnson, Librarian, Oklahoma City Zoo, Oklahoma
City, Oklahoma
• Debra Kachel, Media Specialist, Ephrata Senior High
School, Ephrata, Pennsylvania
• Nina Levine, Media Specialist, Blue Mountain Middle
School, Courtlandt Manor, New York
• Ruth Mormon, Media Specialist, The Meadows School, Las
Vegas, Nevada
B
Barbel: A bit of flesh that dangles from the chins of some turtles.
Bask: To warm up the body, especially by lying in the sun;
basking is seen in such animals as turtles and snakes.
Bay: A part of the sea that cuts into the coastline.
C
Caecilians: Salamanderlike animals that live underground.
Camouflage: A way of hiding or disguising something by mak-
ing it look like its surroundings.
Carapace: The upper shell of a turtle.
Carnivore: An animal that eats meat.
Carnivorous: Meat-eating.
Carrion: Dead animal flesh.
Caruncle: The toothlike part a hatchling reptile uses to break
out of its egg.
Centipede: An animal with a segmented, wormlike body and
many legs.
Clone: An exact duplicate, seen in a mother and her babies of
parthenogenic species.
Cloud forest: A wet, tropical, mountain forest.
Clutch: A nest of eggs.
Cold-blooded: Having a body temperature that changes with
the temperature of the surrounding environment.
Concave: Hollowed or curved inward.
Coniferous forest: A forest with trees that have seeds inside
cones, such as pines; also called evergreen forest.
Constriction: A method snakes use to kill their prey, by wrap-
ping their bodies around the prey animal and squeezing un-
til it cannot breathe.
Constrictor: A snake that squeezes animals, usually to death,
before eating them.
Continent: A large mass of land on planet Earth, such as Africa
or South America.
Continental shelf: A shallow plain in the sea that forms the
border of a continent, usually with a steep slope to the ocean
floor.
Courtship: An animal’s activities that are meant to attract a
mate.
D
Decayed: Rotting.
Deciduous forest: A forest with trees, such as maples, that lose
their leaves in dry or cold weather.
Deflate: To cause to collapse by letting out the air.
Deforestation: Clearing land of trees to use the timber or make
room for human settlement or farming.
Depression: A hollow or a hole.
Dew: Small drops of water that collect on cool surfaces, espe-
cially at night.
Dewlap: The flap of skin that lies under the chin.
Diameter: The width of a circle, measured as a straight line
through the center.
Diurnal: Describing an animal active during the day.
Drought: A dry spell.
Dune: A hill of sand piled up by wind or water.
E
Ectothermic: Describing an animal whose body temperature
changes when the outside air warms up or cools down; of-
ten referred to as “cold-blooded.”
Eggs: The reproductive cells that are made by female animals
and that are fertilized by sperm, or reproductive cells of male
animals.
Embryo: A developing baby that is not yet born.
Endangered: Facing a very high risk of extinction in the wild
in the near future.
Endothermic: Describing an animal that uses its own energy
to maintain a constant body temperature; often referred to
as “warm-blooded.”
F
Fangs: Long, pointed teeth.
Flexible: Movable or bendable.
Forage: A style of hunting in which an animal wanders about
looking for food.
Fossil: The remains, or parts, of animals that lived long ago,
usually found set into rock or earth.
Fossorial species: Those that live underground.
Frill: Pleated or ruffled neck folds.
Fused: Firmly joined together.
G
Genus: Defined by scientists, a group of similar species. A group
of similar genera (the plural of genus) make up a family.
Granular: Grainy like sand.
Grub: A wormlike young insect.
H
Habitat: The natural environment, or living area, of an animal.
Hatchling: A newly hatched young animal.
Herbivore: An animal that eats only plants.
Hibernate: Become inactive during the winter.
Hibernation: A period of inactivity during the winter.
Humus: A material made up of decayed, or rotting, plants and
leaves that feeds soil and holds in water.
I
Incubation: The period of time after eggs are laid and before
they hatch, during which they develop.
Inflate: To make larger or expand.
Infrared vision: The ability to detect, or to “see,” heat.
Invertebrate: An animal, such as an insect, spider, or earth-
worm, that lacks a backbone.
Iridescent: Having the ability to turn light into many colors,
much as rain can bend the sunlight into a rainbow; reflect-
ing different colors depending on the light.
Iridescent scale: Seen in a few snakes, scales that shine dif-
ferent colors depending on how the light hits them.
J
Jacobson’s organ: Common in reptiles, an organ that connects
to the roof of the mouth by a small opening, called a duct,
and helps the animal to smell chemical odors picked up by
the tongue.
Juvenile: A young animal.
K
Keel: A ridge on the upper shell of a turtle.
Keeled scale: On a snake, a scale with a ridge down the middle.
L
Lagoon: A shallow body of saltwater near the sea.
Larva: In many insects, such as beetles and butterflies, the life
stage after the egg and before the pupa.
Ligament: Tough but flexible tissue that connects bones.
Limbs: Legs.
Lineage: A group of animals that connect species through time
to their ancestors.
Live-bearing species: A species, or kind, of animal in which
the females give birth to babies rather than laying eggs.
N
Native: Natural to a country, that is, produced by nature and
not produced or brought in by humans.
Near Threatened: At risk of becoming threatened with ex-
tinction in the future.
Nocturnal: Describing an animal active at night.
Nostrils: Nose holes.
O
Omnivore: An animal that eats both plants and meat.
Omnivorous: Describing an animal that eats both plants and
meat.
Opportunistic: Taking advantage of what is available, as in
feeding on whatever food can be found.
Opportunistic hunters: Animals that will eat almost anything
they happen upon if they are hungry.
Oscillation: In spade-headed wormlizards, the back-and-forth
swiveling motion of the head that digs through the soil and
forms the smooth sides of the tunnel.
Osteoderms: Bony plates that lie under the surface of the scaly
skin in some reptiles, including crocodilians.
Oviparous: Describing an animal that produces and lays
shelled eggs that later hatch into young.
P
Palate: A bony plate on the roof of the mouth.
Parthenogenesis: A type of reproduction where a female can
have babies by herself without a male.
Parthenogenic species: An all-female species in which a female
can become pregnant and have young by herself and with-
out a male.
Pectoral: Relating to the chest area.
Plastron: The lower shell of a turtle.
Pollution: Poison, waste, or other material that makes the en-
vironment dirty and harmful to the health of living things.
Predator: An animal that hunts and kills other animals for
food.
Prey: An animal hunted and caught for food.
Protrude: To stick out.
Pupa: In many insects, such as beetles and butterflies, the life
stage after the larva and before the adult.
Pupil: The part of the eye through which light passes.
R
Rainforest: A tropical woodland area of evergreen trees that
has heavy rainfall all year long.
Range: The area where an animal roams and feeds.
Retract: To pull backward.
Rodent: A small animal, such as a mouse, beaver, or hamster,
with long front teeth that it uses for gnawing.
S
Sac: A pouch.
Sandbar: A ridge of sand built up by currents, or the flowing
movement of water.
Savanna: A flat plain covered with grass and a few trees.
Scale: A clear, thin film or coating over the eyes or a flat, rigid
plate that acts as part of a body covering.
Scent: The particular smell of an animal, which can be left on
the surface over which it travels.
School: A large number of fish or other water-dwelling animals
that swim together.
T
Tail: In snakes, the part of the body that occurs after the vent.
Temperate climate: Describing areas that have distinct sea-
sons, including cold winters.
Tentacles: Long thin body parts used for feeling or for hold-
ing on to things.
Terrestrial: Describing an animal that lives on land.
V
Venom: Poison, usually injected by snakes, bees, or scorpions
by biting or stinging.
Venomous: Poisonous.
Vent: On a snake, a crosswise opening on the belly side and
toward the rear of the animal.
Ventrals: In snakes, the scales on the underside of the animal,
usually much larger than the scales on the snake’s back and
sides.
Vertebrate: An animal that has a backbone.
Vertical: Positioned straight up and down.
Vibrate: To move back and forth rapidly.
Viviparous: Describing a female that makes no eggs, but rather
provides all of the food for her young through direct con-
nections inside her body and gives birth to live babies.
Vocal: Making sounds.
Vocal cord: Body part used to produce sound.
Vulnerable: Facing a high risk of extinction in the wild.
W
Wetland: Land that is covered with shallow water or that has
very wet soil.
Contents xxv
Getting to Know Reptiles
REPTILES
Snakes, crocodiles and alligators, lizards, and turtles might
not look alike at first glance, but they all share certain features.
These animals, plus the tuataras that resemble a cross between
a prehistoric dinosaur and a present-day lizard, are reptiles. In
all, the world holds 285 species of turtles, 23 crocodiles and
alligators, two tuataras, 4,450 lizards, and 2,900 snakes. Scien-
tists suspect that hundreds of other reptile species have yet to
be discovered.
Scales
Almost all reptiles have thick tough skin with scales or
scutes. Alligators have large heavy rectangular scales covering
their bodies, while snakes often have thinner overlapping
scales. Most snakes have larger and wider belly scales, which
are known as scutes. Even turtles have noticeable scales on the
legs and head. These scales and scutes can help protect the rep-
tile from scraping its skin on the ground or from dangerous at-
tacks by other animals that want to eat it. For land-living
reptiles, the scales can also keep the body from drying out too
quickly. Besides the scales on their legs, turtles also have a dif-
ferent type of scutes. The tops of the upper and lower shell are
divided into large pieces, which are also known as scutes.
Reptiles come in many different sizes and colors. Some
snakes grow to less than 12 inches (30.5 centimeters) long as
adults, while others can reach 25 feet (7.7 meters). Likewise, a
whole range of sizes separate the smallest of turtles at just a
Body temperature
Reptiles are often called cold-blooded animals, but this de-
scription is only correct sometimes. A reptile actually changes
its body temperature, becoming hotter when the outside tem-
perature is warm, and colder when the outside temperature is
cool. In other words, a reptile is only “cold-blooded” on cold
days. This changing body temperature is called ectothermy (EK-
toe-ther-mee): ecto means outside and thermy refers to the
temperature. Reptiles, then, are ectothermic animals. In “warm-
blooded” animals, such as human beings, the body has to stay
about the same temperature all the time. If a person’s body tem-
perature rises or falls more than just a few degrees, he or she
can die. For the ectothermic reptiles, however, their body tem-
peratures can swing 20 to 30° F (7 to 13° C)—and sometimes
more—in a single day without causing any harm. Because they
are ectothermic, reptiles do not have to use their energy to stay
warm. Instead, they can simply let the sun warm them up by
sunbathing, or basking, on a forest path or the shore of a river
or lake. Ectothermy can also have a downside. Reptiles are
slower on cooler days or in the cool morning or evening air,
which can make them easy prey for attackers. Most reptiles,
Venom
Not all reptiles are venomous, but many
snakes and a few lizards are. Venom is a type
of toxin, or poison. Venomous snakes gen- FLYING REPTILES?
erally have two fangs in their upper jaw— No reptiles can actually fly, but several
sometimes in the front of the mouth and can glide through the air much like a
sometimes in back. These fangs usually have paper airplane. The flying tree snake,
grooves that send the venom down the tooth which is common in Singapore, flattens
and into the prey. Unlike the snakes, the two out its body to soar from one tree branch
venomous lizards, the Gila monster and the to a lower one. The common gliding lizard,
Mexican beaded lizard, store their venom in also known as the common flying dragon,
the lower jaw and deliver it through grooves can likewise glide through the air, but it
in numerous teeth. does so by stretching out a large flap of
skin, as if opening a fan, on each side of
HOW DO REPTILES MOVE? the body. The flying geckos of Southeast
Walking Asia have numerous little flaps on their
Although not all reptiles have legs, many body, tail, legs, and head that help them
of them do. Crocodiles and alligators, turtles, to glide.
most lizards, and tuataras can walk on their
four legs. Each leg ends in a foot with five or
fewer claws. Usually they walk with their legs held out from
the body, rather like a human would hold up his or her body
when doing a push-up. Many of the smaller lizards, in partic-
ular, are very speedy, zipping across the ground at speeds that
make their capture difficult. The exceptionally large lizards,
known as Komodo dragons, usually walk very slowly, as do
crocodiles, which often slide their bellies along the ground
while walking. If necessary, however, both can run surpris-
ingly fast. A few reptiles, such as the Nile crocodile and Amer-
ican crocodile, can even do a fast rabbitlike hop, called a gallop,
to cover ground quickly. Some lizards can run on just their
two hind legs, and the basilisk lizard is even able to run across
the surface of a pond without sinking.
Slithering
Snakes slither, usually twisting and bending their bodies in
an S-shaped pattern along the ground. This type of movement
is called serpentine (SER-pen-teen) locomotion. Like the
snakes, some lizards also have no legs. They move much the
The green basilisk lizard is able same way as snakes do. Occasionally, some lizards that have
to run across water aided by
the flaps of skin on the
legs will slither instead of run. When they are in thick grass
underside of its hindfeet. that makes running very difficult, some will lie down, hold the
(Illustration by Emily Damstra. legs against the body, and begin to slither.
Reproduced by permission.)
Swimming
Many turtles, alligators, and crocodiles spend most of their
lives in the water. Turtles often have wide feet that they use to
push them through the water. A few, like the seaturtles, even
Plant eaters
A few reptiles, especially some of the turtle
species and a few lizards, eat plants. Animals
that eat plants are called herbivores (ER-bih-
vores). A few animals will eat both meat and plants. These are Seaturtle swimming strokes.
called omnivores (OM-nih-vores). Some turtles, including the (Illustration by Patricia Ferrer.
commonly seen painted turtles, will switch from a mostly meat Reproduced by permission.)
diet to one that is mostly plants when animal prey are hard to
find.
Freshwater reptiles
Alligators and crocodiles, many turtles, some snakes, and a
few lizards live in freshwater lakes, ponds, rivers, and streams.
Depending on the species, they may spend a good deal of time
every day on shore basking in a sunny spot. Some will even do
some hunting on land. Crocodiles, for instance, may grab a prey
animal on shore but will then drag it into the water to drown it.
Sea reptiles
Among the reptiles, the seaturtles are most known for their
association with the oceans. With their paddlelike front legs,
they can glide easily through the water and cover very long dis-
tances, often migrating hundreds of miles (kilometers) between
their nesting beaches in warm climates and their feeding areas
in cooler climates. The leatherback seaturtle migrates the far-
thest, taking trips of up to 3,100 miles (5,000 kilometers) from
its nesting place to a feeding site. Some snakes also live in the
ocean. The seasnakes make their home in coral reefs, where
they eat eels and fishes.
Tree reptiles
Animals that live in trees are said to be arboreal (pronounced
ar-BOR-ee-ul). Some reptiles are arboreal. These include many
snakes, even large ones like the emerald tree boa that can grow
to 7.3 feet (2.2 meters) in length. Many lizards are also excel-
lent climbers and slither through trees looking for insects or
bird eggs to eat.
REPRODUCTION
Most female reptiles lay eggs, but some give birth to babies.
Some of the newborn babies may have actually hatched from
eggs while they were still inside the mother. Female reptiles all
lay their eggs or give birth to their babies on land. Even those
that live in the water for the rest of the year crawl onto shore
to have their young. Tuataras lay eggs in their burrows. Some
female turtles and crocodiles bury their eggs on shore or far-
ther inland. A few turtle species lay their eggs in leaf piles. Af-
ter laying the eggs, a female turtle leaves the nest, and the young
are on their own. Crocodiles care for their young, bringing the
new hatchlings from the nest site to the water. Snakes and
3
4
lizards may lay eggs or have babies. In some species, the female Egg laying strategies.
1. Peninsula cooter turtle;
may remain with the eggs and/or the young, although scien- 2. American alligator;
tists are unsure how much real protection or care many of the 3. Python; 4. Copperhead.
mother snakes actually provide. (Illustration by Dan Erickson.
Reproduced by permission.)
ENDANGERED REPTILES
Reptiles in danger
Many, many species of reptiles may disappear from the
Earth soon, if they do not receive some protection. Two-
3 4
5 6
Reptilian visual displays: thirds of all turtle species, for example, are now listed by the
1. Cottonmouth uses gaping
mouth as a defensive warning;
World Conservation Union (IUCN) as being at risk. Overall,
2. Frilled lizard looks larger as a the IUCN counts 453 species of reptiles, or more than one
defensive display; 3. A ringneck in every six species, as being at some risk. Moreover, scien-
snake draws attention away
from its head and shows its tists know so little about many species that others may be at
coloration as a defense; 4. The risk, too.
alligator snapping turtle uses a
food lure to attract its prey; The decline in reptile populations is commonly a result of
5. and 6. Territorial or mating habitat destruction or of overhunting for their meat or skin or
displays for green anole (5) and for the pet trade. For turtles, much of the danger comes from
tuatara (6). (Illustration by Dan
Erickson. Reproduced by the growing number of predator animals that dig up turtle nests
permission.) and eat the eggs. Scientists estimate, for instance, that 75 to 90
Periodicals:
Barr, Brady, and Margaret Zackowitz. “The Big Squeeze. (The
Icky Adventure of Brady Barr).” National Geographic Kids.
May 2003, page 40.
Calvert, Pam. “Out of Control!: The Brown Tree Snake.”
Odyssey. April 2000, page 23.
Chiang, Mona. “The Plight of the Turtle.” Science World. May
9, 2003, page 8.
Gill, Paul G., Jr. “Red on Yellow, Kill a Fellow! Get Snake-smart
before Heading into the Wild.” Boys’ Life. April 2004, page
26.
Mealy, Nora Steiner. “Creatures from Komodo.” Ranger Rick.
August 2001, page 18.
Web sites:
“All About Turtles.” Gulf of Maine Aquarium. http://octopus
.gma.org/turtles/ (accessed on November 1, 2004).
“How fast can a crocodile run?” Crocodilian Biology Database,
Florida Museum of Natural History. http://www.flmnh.ufl
.edu/natsci/herpetology/brittoncrocs/cbd-faq-q4.htm (accessed
on November 1, 2004).
“Reptiles.” Environmental Education for Kids. http://www.dnr
.state.wi.us/org/caer/ce/eek/critter/reptile/index.htm (accessed
on November 1, 2004).
“Reptiles.” San Diego Natural History Museum. http://www.sdnhm
.org/exhibits/reptiles/index.html (accessed on November 1,
2004).
“Snakes.” Defenders of Wildlife. http://www.kidsplanet.org/
factsheets/snakes.html (accessed on November 1, 2004).
Sohn, Emily. “The Cool Side of Snake Pits.” Science News for
Kids. http://www.sciencenewsforkids.org/articles/20030625/
Note2.asp (accessed on November 1, 2004).
Sohn, Emily. “Delivering a Little Snake Venom.” Science News
for Kids. http://www.sciencenewsforkids.org/articles/20030903/
Feature1.asp (accessed on November 1, 2004).
Trivedi, Bigal P. “Smallest Known Lizard Found in Caribbean.”
National Geographic. http://news.nationalgeographic.com/
news/2001/12/1203_TVtinylizard.html (accessed on Novem-
ber 1, 2004).
●
Number of orders: 2 orders
order C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The dinosaurs are a large group of reptiles that lived from class
230 to 65 million years ago. Some, such as the well-known
subclass
Tyrannosaurus rex, were enormous meat-eating animals. Oth-
ers, however, were small and timid creatures that nibbled on ● order
plants. monotypic order
Scientists divide the dinosaurs into two orders. One order is
suborder
Saurischia, which includes the theropods (THAIR-oh-pods)
that walked on their two hind legs and were mostly meat-eat- family
ing dinosaurs and the sauropods (SAWR-oh-pods) that walked
on all fours and ate plants. The theropods had more primitive
features, including jagged teeth, and some, such as the Cer-
atosaurus, had hornlike knobs jutting out of their skulls. Tyran-
nosaurus rex was a theropod. Although it was quite large at 40
to 50 feet (12.2 to 15.2 meters) long, its ancestors only grew
to about 10 feet (3 meters) long.
The sauropods looked much different than the theropods.
They had very long necks and tiny heads. Some of them were
able to lift their front legs off the ground and grab leaves or
other things with their hands. Other species, including Bra-
chiosaurus, had longer front legs than hind legs, similar to the
arrangement in current-day giraffes. Their tall front legs, com-
bined with their overly long necks, helped them easily reach
food even at the tops of most trees.
The other order within the dinosaurs is Ornithischia, which
included those dinosaurs that ate plants and had hip bones that
looked like those found in present-day birds. Many of them had
Dinosaurs 1
crests, beaks, horns, or helmets, and some had armor-like
plates, called scutes, covering their bodies and occasionally
spikes. Stegosaurs are an example of an Orinithischian. These
dinosaurs had armor-like spines down the middle of the back
and spiked tails. The Ornithischia also includes the duckbill di-
nosaurs with their wide snouts.
Within these two orders of dinosaurs, the animals are fur-
ther split into several hundred smaller groups, called genera
(jen-AIR-uh). One or more species is grouped into each genus
(JEAN-us), which is the singular of genera.
Although the name dinosaur actually means “terrible
lizards,” dinosaurs are not lizards and are different from all
other groups of reptiles. One of the major differences between
dinosaurs and other reptiles is in the way they moved. Lizards
and crocodiles walk with their legs held out to the side, in the
same type of position a person’s arms take when doing pushups.
A few dinosaurs sprawled their front legs like a lizard, but the
vast majority of them walked like a dog or cat—with the legs
directly below the hips and shoulders.
Many scientists also now suspect that at least some of the
dinosaurs were warm-blooded, instead of cold-blooded like
other reptiles. A warm-blooded animal, more properly called
an endothermic (EN-doe-THER-mik) animal, uses its own en-
ergy to keep its body at a constant temperature. Cold-blooded,
or ectothermic (EK-toe-THER-mik), animals get their body heat
from an outside source, like the warmth of the sun.
Dinosaurs came in many shapes and sizes. The Seismosaurus,
or “earth-shaking dinosaur,” may have been the longest at 120
to 150 feet (36.6 to 45.7 meters) long. The heaviest may have
been the Argentinosaurus, which grew to 100 to 130 feet (30.5
to 39.6 meters) long and weighed 110 tons (99,800 kilograms).
Other enormous dinosaurs include the Supersaurus at 100 feet
(30.5 meters) long and about 50 tons (45,000 kilograms) and
the Brachiosaurus at 85 feet (25.9 meters) long and about 75
tons (68,000 kilograms). The Tyrannosaurus rex, a name that
is often shortened to T. rex, was considerably smaller at 40 to
50 feet (12.2 to 15.2 meters) long and 6 tons (5,400 kilograms)
in weight. Since T. rex stood on its hind legs rather than on all
fours, it towered over most other dinosaurs. Other similarly
sized meat-eating dinosaurs were the Gigantosaurus, Spin-
osaurus, and Carcharodontosaurus. All dinosaurs were not gi-
ants, however. Some, such as the Saltopus and Lesothosaurus,
GEOGRAPHIC RANGE
The Earth that the early dinosaurs knew looked much dif-
ferent than the Earth does today. The planet had a single, huge
land mass, called Pangaea, and the dinosaurs lived over much
of this area, particularly in the warmer climates. About 180 mil-
lion years ago—50 million years after the dinosaurs first
evolved—Pangaea began to split up and eventually formed the
continents seen on Earth today. Given such huge changes, a fos-
sil found nowadays in Germany, for example, says nothing about
the location of the dinosaur that left it 220 million years ago.
HABITAT
Because scientists are studying fossils from many millions of
years ago, rather than living animals, they usually cannot tell
much about the dinosaur’s habitat. They do, however, suspect
that none of them lived in the water. Although a few dinosaurs
may have been able to keep their bodies afloat for brief peri-
ods, or could wade to catch fish, none were full-time swim-
mers. Some scientists believe that sauropod dinosaurs may have
been able to float and, based on footprints left behind, think
they pushed themselves along by bouncing their front feet on
the bottom of the pond or lake.
DIET
About two-thirds of all genera contain dinosaurs that were
plant eaters, and a third of the genera include meat-eating di-
nosaurs. Scientists can determine whether a dinosaur ate meat
or plants by looking at its teeth. The teeth of meat-eaters, also
known as carnivores (KAR-nih-voars), are pointed for tearing
flesh. The teeth of a plant-eater, or herbivore (ER-bih-voar), are
flatter for grinding grasses and leaves. Studies of other dinosaur
bones can also reveal information about their diet. One study,
for instance, showed that some dinosaurs were cannibals. By
looking at teeth marks on the bones of certain dinosaurs and
comparing the marks to the teeth of the same species, the sci-
entists figured out that the reptile was eating its own kind. This
particular species, a theropod called Majungatholus atopus, grew
to 29.5 feet (9 meters) long.
Dinosaurs 3
BEHAVIOR AND REPRODUCTION
With almost nothing but fossils to study, scientists can only
guess at most dinosaur behavior. For example, although T. rex
is often described as a ferocious predator, scientists only know
that it had a skeleton that likely supported a strong body, and
it had the jaws and teeth necessary to eat large prey animals.
It is possible, however, that T. rex never even attacked live an-
imals, but instead ate only animals that were already dead. Re-
cently, scientists think they may have found evidence that some
dinosaurs were social animals, which means that they spent
time together in groups. They based this idea on a fossil find
in Patagonia, where the bones of six, large, carnivorous di-
nosaurs were found huddled together in one area. The scien-
tists think the dinosaurs, a new species that measures 40 feet
(12.2 meters) long and had sharp and bladelike teeth, may have
hunted together so they could attack and kill sauropods that
grew to at least twice their size. Scientists believe some di-
nosaurs were social because their bones suggest that they were
able to make loud noises. The lambeosaurs, for instance, had
sound-producing tubes inside the skull, and scientists suspect
that the animals communicated with one another.
Scientists sometimes find dinosaur footprints that have been
preserved over time. From these, they can learn how the ani-
mal moved. Footprints of ornithomimids, which were ostrich-
like dinosaurs, show that they could run at least 25 miles (40
kilometers) an hour, while those of a 3-foot-long (9 meter) meat
eater called a Megalosaurus could zip along on its hind legs at
speeds of 29 miles (48 kilometers) an hour. By looking at the
bones of dinosaurs, scientists can also guess their fastest run-
ning speed. A recent study of T. rex bones shows that it prob-
ably could run no faster than the much smaller ornithomomids.
Scientists have recently found many dinosaur eggs, some of
them with young still inside. A group of Allosaurus eggs found
in Portugal provided some clues to the way they were born. The
egg shells were covered with tiny holes, called pores, and looked
very much like the pore-covered eggs of current-day crocodil-
ians. The pores allow air to flow into the eggs, so the growing
babies can breathe. Based on these findings, scientists believe the
female dinosaurs of this species laid their eggs in mounds of veg-
etation or buried them, just as the now-living crocodilians do.
One of the best places in the world to find dinosaur fossils is
Mongolia. In 1993, scientists learned that it was also an excellent
CONSERVATION STATUS
The dinosaurs became extinct 65 million years ago. Their
deaths likely resulted from a huge asteroid, a rock from outer
space, that slammed into the Earth, probably near the Yucatan
Peninsula of Mexico. The impact from the 4 to 9 mile-wide (6
to 15 kilometer) asteroid sent up a thick plume of dust and
caused a chain reaction that resulted in a severe change in the
planet’s climate. For years afterward, the sun was unable to pen-
etrate the dark curtain of dust. Temperatures around the world
began to drop. Without sunlight, plants died, and with fewer
plants to eat, many herbivores also perished. With fewer and
Dinosaurs 5
fewer herbivores to eat, the carnivores may have begun to eat
each other, until they also disappeared. Scientists believe that
one group of dinosaurs survived the great extinction, however.
These were the dromaeosaurids that eventually evolved into the
birds. For this reason, some books refer to birds as modern-
day dinosaurs.
Books:
Farlow, James O., and M. K. Brett-Surman, eds. The Complete Dinosaur.
Bloomington and Indianapolis: Indiana University Press, 1997.
Haines, Tim. Walking with Dinosaurs: A Natural History. New York: Dorling
Kindersley, 2000.
Holta, Thomas R., Michael Brett-Surman, and Robert Walters. Jurassic
Park Institute (TM) Dinosaur Field Guide. New York: Random House
Books for Young Readers, 2001.
Lambert, David, and Steve Hutt. DK Guide to Dinosaurs. New York: Dorling
Kindersley, 2000.
Paul, Gregory S., ed. The Scientific American Book of Dinosaurs. New
York: St. Martin’s Press, 2000.
Weishampel, David B., Peter Dodson, and Halszka Osmólska, eds. The
Dinosauria. Berkeley: University of California Press, 1990.
Periodicals:
Adams, Judith. “Footsteps in Time.” Faces: People, Places, and Cultures.
April 2003, vol. 19: 30.
Hesman, Tina. “Dinosaurs, party of six, meat eating.” Science News. April
1, 2000, vol. 157: 223.
Mandel, Peter. “Dino Might! 10 Recent Discoveries That Have Rocked
the Dinosaur World.” National Geographic Kids. March 2003: 14.
Davy, Emma. “Crash Test: What Wiped Out the Dinosaurs? Scientists
Studying an Enormous Crater in Mexico Hope to Find the Answer.” Current
Science. September 27, 2002, vol. 88: 6.
Perkins, Sid. “Bob, Bob, Bobbin’ Along: Dinosaur Buoyancy May Explain
Odd Tracks.” Science News. October 25, 2003, vol. 164: 262.
Web sites:
“Dinosaur embryo.” American Museum of Natural History. http://
www.amnh.org/exhibitions/expeditions/treasure_fossil/Treasures/
Dinosaur_Embryo/embryo.html?dinos (accessed on December 22,
2004).
Dinosaurs 7
TURTLES AND TORTOISES
Testudines
●
Class: Reptilia
Order: Testudines
Number of families: 14 families
order C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Turtles and tortoises, which are in the order Testudines, have
bony upper and lower shells that surround much of the body. The
subclass
upper shell, or carapace (KARE-a-pays), can be tall and rounded,
● order can be flat, or can be some shape in between. The lower shell, or
monotypic order plastron (PLAS-trun), can cover most or just a portion of the bot-
tom of the animal, depending on the species. In most cases, the
suborder upper shell connects to the lower shell by way of a bony bridge.
family In some species, the bridge is made of more flexible tissue called
ligament (LIH-guh-ment). The hard shell often is covered with
large scales called scutes (SCOOTS). In some species, new scutes
grow under the old ones, and the old ones pile up. A person can
count the number of scutes in the pile to tell how old the turtle
is. Softshell turtles have no scutes. They do have small bony shells,
but the bones are covered with leathery or rubbery skin.
Besides shells, another feature of turtles and tortoises is that
they have no teeth. Instead they have hard, flat surfaces on their
jaws that allow them to grip and tear off bits of plants or ani-
mals for feeding. Sometimes these surfaces come to a sharp
point in front and look much like the hook on the end of a
hawk’s or eagle’s beak. Turtles with such pointed upper jaws
are often said to have horny beaks.
Turtles and tortoises, like birds, dogs, humans, and other an-
imals, are vertebrates (VER-teh-brehts), which means they have
a backbone. Turtles and tortoises are unlike all other vertebrates
in that their hip and shoulder bones are inside the rib cage in-
stead of outside because the ribs are attached to the upper and
GEOGRAPHIC RANGE
Turtles and tortoises live on all continents except Antarctica.
HABITAT
Depending on the species, turtles and tortoises can live on
land, in fresh water, in the ocean, and along the coast. They
live on many of the larger islands of the oceans and on every
continent of the world except Antarctica.
DIET
Some species of turtles and tortoises are almost completely
vegetarian, some eat almost nothing but meat, and still others
eat a mix of meat and plants. Many turtles are opportunistic (ah-
per-too-NIS-tik) feeders, meaning that they eat just about any-
thing they can find, from fruits and leaves to live tadpoles and
bits of dead fish. In some species, baby turtles eat mostly insects
and other meat but switch to mostly plants as they get older.
Books:
Behler, John L., and F. Wayne King. The Audubon Society Field Guide to
North American Reptiles and Amphibians. New York: Knopf, 1979.
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. London: Dorling Kindersley, 2001.
Conant, Roger, and Joseph T. Collins. A Field Guide to Reptiles and
Amphibians of Eastern and Central North America. 3rd ed. Boston:
Houghton Mifflin, 1998.
Ernst, C. H., and R. W. Barbour. Turtles of the World. Washington, DC:
Smithsonian Institution Press, 1989.
Ernst, C. H., J. E. Lovich, and R. W. Barbour. Turtles of the United States
and Canada. Washington, DC: Smithsonian Institution Press, 1994.
Harding, J. H., and J. A. Holman. Michigan Turtles and Lizards. East
Lansing: Michigan State University, 1990.
Pough, F. H., R. M. Andrews, J. E. Cadle, M. L. Crump, A. H. Savitzky, and
K. D. Wells. Herpetology. Upper Saddle River, NJ: Prentice Hall, 1998.
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians.
3rd ed. Boston: Houghton Mifflin, 2003.
Zug, G. R., L. J. Vitt, and J. P. Caldwell. Herpetology: An Introductory
Biology of Amphibians and Reptiles. San Diego, CA: Academic Press, 2001.
▲
Class: Reptilia
Order: Testudines
Family: Carettochelyidae
One species: Pig-nose turtle
(Carettochekys
insculpta)
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
This family has only one member: the pig-nose turtle. This is class
quite a large freshwater turtle, with an upper shell that can reach subclass
22 inches (56 centimeters) in length and 14 inches (35.6 cen-
timeters) in width. It may weigh up to 50 pounds (22.7 kilo- order
grams). It often swims with just its long snout sticking out of the monotypic order
water. That long snout is one of its most notable features. A fleshy, suborder
tube-shaped structure, it is similar in appearance to the snout of
a pig. The shell of the pig-nose turtle is also different from that ▲ family
of most other turtles. The shells of most turtles are covered in
bony plates, called “scutes” (SCOOTS). The pig-nose turtle, on
the other hand, has a hard shell with a leathery covering.
This turtle also has long front legs that can stretch to a length
almost half as long as the carapace (KARE-a-pays), or upper
shell. The legs are flat and wide, like paddles or flippers. In
fact, the limbs, or legs, more nearly look like the front legs of
marine turtles, or turtles that live in the sea, than those of other
freshwater turtles. Each front limb is tipped with two claws. In
color, the turtle is mostly olive or gray on the tops of its limbs
and high-domed upper shell and is whitish or yellowish on its
bottom shell, or plastron (PLAS-trun), and on its chin, lower
neck, and the undersides of its limbs. Males and females look
very much alike, except for the male’s larger tail. Besides their
smaller size, juveniles (JOO-vuh-nuhls), or young turtles, dif-
fer from adults in the smoothness of the carapace. The juvenile
carapace has a lumpy ridge, called a “keel,” down the middle
and is jagged along the edge, whereas the adult carapace does
Pig-nose Turtle 13
not have a keel anywhere except toward the
back, and it is rounded at the edge.
At one time scientists believed that these
turtles should be included with the side-
necked turtles, a group known as the Pleu-
rodira, rather than the hidden-necked turtles,
A TURTLE BY ANY OTHER NAME or the Cryptodira. The better-known hidden-
Although the family Carettochelyidae necked turtles pull their heads and necks
contains only one species, a person might straight back into their shells, whereas side-
think several exist. The reason is that the necked turtles fold their necks sideways. Sci-
one species, Carettochelys insculpta, goes entists based their decision mostly on the
by the common names pig-nose turtle, pig- location of the first turtle discovered back in
nosed turtle, Fly River turtle, and pitted- the late 1800s. The original specimen (SPEH-
shelled turtle, to name just a few. They are suh-muhn), or example, was not whole; it was
one and the same turtle. Sometimes missing the part of its backbone that would
common names describe a body feature. have shown scientists whether it was a side-
For instance, “pig-nose” refers to the necked or a hidden-necked turtle. Because it
turtle’s piglike snout. Common names can was found in New Guinea and all of the other
also identify the species’ home. “Fly River,” turtles known from New Guinea or from Aus-
for example, names one of the places the tralia at that time were of the side-necked va-
turtle is found in New Guinea. riety, the scientific community assumed that
the pig-nose turtle must be a side-necked tur-
tle too. As more of these turtles turned up,
however, scientists were able to take a closer look at the back-
bone, and they discovered that this species should be considered
a hidden-necked turtle.
GEOGRAPHIC RANGE
This turtle is found in southern New Guinea and northern
Australia.
HABITAT
The pig-nose turtle usually lives in freshwater rivers, lakes,
swamps, and other water bodies with shady shorelines. Some-
times it makes its home in saltier estuaries (EHS-chew-air-eez),
or the wide parts at the lower end of rivers that link these water
bodies to the ocean. They tend to prefer slower-moving and even
unmoving waters that have soft bottoms of silt, or loose earth, on
top of sand or gravel. The pig-nose turtle is sometimes also called
Fly River turtle, because it is found in the Fly River in Papua,
New Guinea. Scientists once thought the turtle lived only in New
Guinea, but ten of the turtles were discovered in Australia’s Daly
DIET
Pig-nose turtles will eat just about anything they can find.
They seem to prefer plants; they especially like figs and other
fruits that drop from trees along the shoreline, but they will eat
leaves, flowers, underwater plants, and the tiny plantlike
growths called algae (AL-jee). They will also eat hard cones that
require a solid bite to break open. They are not strict plant
eaters, however. If the turtles find the wormlike young form of
an insect, called a “grub”; a beetle; or an ant, they will eat those
too. They will even partake of freshwater snails or other mol-
lusks, crustaceans (krus-TAY-shuns) such as shrimp, or even
dead mammals or birds.
Pig-nose Turtle 15
Pig-nose turtle (Carettochelys insculpta)
CONSERVATION STATUS
Collection of the pig-nose turtle for food
and as pets, combined with loss or destruction
of their habitat, or preferred living areas, have
all threatened this turtle. The World Conser-
vation Union (IUCN) has given its status as
Vulnerable, meaning that it faces a high risk
of extinction, or dying out, in the wild. Log-
Pig-nose turtles often swim with
ging and farming can destroy waterside plants and drastically just their long snouts sticking
increase erosion (ih-ROH-zhen), or wearing away of the land, out of the water. (Illustration by
both of which can affect the turtles. In addition, the passage of Barbara Duperron. Reproduced
by permission.)
water buffalo on their way to watering holes may also hurt the
turtles’ chances of survival. The buffalos crush the plants that
the turtles eat, and they also trample across the beaches used
by the turtles to lay their eggs. Heavy foot traffic can destroy
the nests and the eggs inside.
Books:
Cann, John. Australian Freshwater Turtles. Singapore: Beaumont
Publishing, 1998.
Periodicals:
Bargeron, Michael. “The Pig-nosed Turtle, Carettochelys insculpta.”
Tortuga Gazette 33, no. 3 (March 1997): 1–2.
Web sites:
“Carettochelyidae.” Herpetology: Reptiles and Amphibians. http://www
.nafcon.dircon.co.uk/Carettochelyidae.htm (accessed on August 19,
2004).
“The Pig-nosed Turtle.” University of Canberra Australia Applied Ecology
Research Group. http://aerg.canberra.edu.au/pub/aerg/herps/fncchely
.htm (accessed on August 2, 2004).
Pig-nose Turtle 17
AUSTRALO-AMERICAN SIDE-
NECKED TURTLES
Chelidae
▲
Class: Reptilia
Order: Testudines
Family: Chelidae
Number of species: 50 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Australo-American side-necked turtles are a varied group of
medium-sized to rather large turtles with necks that fold sideways
subclass
under their shells, rather than retracting, or pulling backward,
order into the shell. In some cases, the neck can be as long as the up-
monotypic order per shell, or carapace (KARE-a-pays) or even longer. A few side-
necked turtles, however, have very short necks. Depending on
suborder the species, the upper shell of adults can range in length from 6
▲ family to 19 inches (15–48 centimeters). Most turtles have dark upper
shells, and a few have brightly colored lower shells, or plastrons
(PLAS-truns); heads; necks; legs; or tails. These parts of the body
may be red, orange, or yellow. Often, the juveniles (JOO-vuh-
nuhls), or young turtles, are the most brightly colored; the color
fades as they age. Some of these turtles have glands, or special or-
gans, that give off a bad smell, which wards off predators, or other
animals that hunt and kill the turtles. Males and females look
quite similar, although the females in most species are larger than
the males. In a few cases, the males have especially long tails that
they may use in mating with females.
GEOGRAPHIC RANGE
These turtles range across New Guinea, Australia, Indone-
sia, and South America.
HABITAT
The Australo-American side-necked turtle typically lives in
freshwater lakes, ponds, rivers, and streams that are always
filled with water, but they spend part of their time in wetlands
CONSERVATION STATUS
The World Conservation Union (IUCN) lists three species
as Critically Endangered, or facing an extremely high risk of
extinction, or death, in the wild, and four as Endangered, or
facing a very high risk of extinction. Six are Vulnerable, mean-
ing that they face a high risk of extinction, and eight are Near
Threatened, meaning that they face the risk of becoming ex-
tinct in the near future. One of the Critically Endangered tur-
tles is the western swamp turtle, of which fewer than four
hundred individuals survived in 2003, and all live in a few small
areas of Brazil. Another turtle, called Hoge’s side-necked tur-
tle, is also very rare, existing in just a few spots in the same
country. The U.S. Fish and Wildlife Service lists two species as
Endangered. The main reason for concern about these species
is loss of their habitat, through either damage or complete de-
struction. Efforts are under way to save these threatened species
from extinction by removing them from the wild and breeding
them in captivity, possibly for future release back into the wild.
SPECIES
MATAMATA ACCOUNT
Chelus fimbriatus
sometimes just its tube-shaped nose breaks the water’s surface as the
turtle moves about underwater. Females usually are larger than males.
Books:
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. London: Dorling Kindersley, 2001.
Cann, John. Australian Freshwater Turtles. Singapore: Beaumont Pub-
lishing, 1998.
Pritchard, Peter C. H., and Pedro Trebbau. The Turtles of Venezuela.
Athens, OH: Society for the Study of Amphibians and Reptiles, 1984.
▲
Class: Reptilia
Order: Testudines
Family: Cheloniidae
Number of species: 6 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The seaturtles are large animals that live in the ocean. Their
upper shell, or carapace (KARE-a-pays), is quite flat rather than
subclass
highly rounded. The lower shell, or plastron (PLAS-trun), is a
order bit smaller than in most turtles and attaches to the upper shell
monotypic order by tough but flexible tissues called ligaments (LIH-guh-ments),
rather than the bony bridge common to land turtles. Seaturtles
suborder are excellent swimmers, gliding through the water with sweeps
▲ family of their large, broad, and powerful front limbs, which look like
flippers or paddles. Unlike many other turtles, they cannot re-
tract, or pull back, their limbs or heads into their shells. The
largest members of the family, the leatherback seaturtles, tip
the scales at half a ton (454 kilograms) or more. The
leatherbacks have a carapace that measures 6 to 7 feet (1.8–2.1
meters) in length.
GEOGRAPHIC RANGE
Seaturtles inhabit all the oceans of the world and the Mediter-
ranean Sea.
HABITAT
These turtles live in saltwater from the tropics to areas with
mild climates well north and south of the equator, the imagi-
nary circle around Earth that is midway between the poles. They
are more common close to shore than far out to sea, and they
feed and nest at sites along the coastlines on continental shelves,
or shallow plains forming the borders of continents.
Seaturtles 25
mon. The eggs hatch in forty to seventy days. As with most tur-
tles, the outdoor temperature during their incubation (ing-
kyuh-BAY-shun), or the period of time before the eggs hatch,
determines whether the egg will become a male or female upon
hatching. When the weather is warm, more females hatch;
males usually hatch when the weather is cooler.
CONSERVATION STATUS
The World Conservation Union (IUCN) lists the olive rid-
ley, loggerhead, and green seaturtles as Endangered, meaning
that they face a very high risk of extinction in the wild in the
near future. The hawksbill and Atlantic ridley seaturtles are
Critically Endangered, meaning that they face an extremely
high risk of extinction in the wild in the near future. Hunting
and egg collecting, along with dangers that come from shrimp-
ing and fishing practices, are responsible for much of the de-
cline in turtle numbers. The U.S. Fish and Wildlife Service lists
the olive ridley seaturtle as Threatened, meaning that it is likely
to face the danger of extinction in the near future in the United
States. Certain populations of green seaturtle are Endangered,
and others are Threatened. The hawksbill and Kemp’s ridley
are Endangered, and the loggerhead is Threatened.
SPECIES
GREEN SEATURTLE ACCOUNTS
Chelonia mydas
Diet: Adult green seaturtles spend much of the daylight hours munch-
ing on sea grasses and algae, which are the main items of their diet.
Only rarely do they eat a bit of meat, such as a sponge or jellyfish. Some
Seaturtles 27
The upper shell of the green
seaturtle can measure 5 feet
(1.5 meters) in length, and the
turtle itself can weigh as much
as 750 pounds (340 kilograms).
(©Dr. Paula A. Zahl/Photo
Researchers, Inc. Reproduced by
permission.)
scientists believe that the young may eat much more meat, but there is
no evidence that they do.
Seaturtles 29
Loggerhead turtle (Caretta caretta)
LOGGERHEAD TURTLE
Caretta caretta
Habitat: For the breeding season, this saltwater turtle prefers tropi-
cal waters in protected areas, such as bays, or parts of the sea that cut
into a coastline, and estuaries (EHS-chew-air-eez), or the wide parts
at the lower ends of rivers, where the river meets the sea. The turtle
travels well into temperate regions during the remainder of the year.
Diet: Meat is the primary food of both young and adult loggerheads.
Hatchlings, or newly hatched turtles, will also eat pieces of the algae
mats among which they float, and adults will munch on underwater
plants and algae. Favored food items for adults include snails and
other mollusks, sponges, squid, and fishes.
Loggerhead turtles and people: Some people still hunt this turtle
and collect its eggs for food.
Seaturtles 31
FOR MORE INFORMATION
Books:
Bjorndal, Karen A. Biology and Conservation of Sea Turtles. Washington,
DC: Smithsonian Institution Press, 1995.
Dunbier, Sally. Sea Turtles. Hauppauge, NY: Barron’s Educational Service
Series, 2000.
Kalman, Bobbie. The Life Cycle of a Sea Turtle. New York: Crabtree
Publishing, 2002.
Laskey, Kathryn. Interrupted Journey: Saving Endangered Sea Turtles.
Cambridge, MA: Candlewick Press, 2001.
Lutz, Peter L., and John A. Musick, eds. The Biology of Sea Turtles. 2
volumes. Boca Raton, FL: CRC Press, 1996–2003.
O’Keefe, M. Timothy. Sea Turtles: The Watcher’s Guide. Lakeland, FL:
Larsen’s Outdoor Publishing, 1995.
Web sites:
“Animal Bytes: Sea Turtles.” Animals. http://www.seaworld.org/animal
info/animalbytes/animalia/eumetazoa/coelomates/deuterostomes/
chordates/craniata/reptilia/testudines/sea-turtles.htm (accessed on
September 7, 2004).
“Sea Turtles for Kids.” Kidz Korner. http://www.turtles.org/kids.htm
(accessed on September 7, 2004).
“Turtles in Trouble.” National Geographic Kids. http://www.nationalgeo
graphic.com/ngkids/9911/turtle (accessed on September 7, 2004).
▲
Class: Reptilia
Order: Testudines
Family: Chelydridae
Number of species: 4 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
Snapping turtles are large, unfriendly turtles that have strong, class
clawed legs; a powerful bite; and a long neck. With its long
subclass
neck, the snapping turtle can quickly swing its large head far
forward as well as sideways and back over the upper shell. These order
turtles also have a long, strong tail with a row of ridges. The monotypic order
upper shell, or carapace (KARE-a-pays), has three keels, or
ridges, but older turtles usually lose the keels and have smooth suborder
shells. The lower shell, or plastron (PLAS-trun), is quite small, ▲ family
which allows the turtle to move its legs easily. The length of
an adult’s upper shell ranges from 7.1 to 31.5 inches (18 to 80
centimeters), and the lower shell may be only about one-fourth
that size. Females weigh about 4.4 to 5.5 pounds (2 to 2.5 kilo-
grams). Males generally are larger than females and can weigh
as much as 249 pounds (113 kilograms).
GEOGRAPHIC RANGE
Snapping turtles live in North America, Central America, and
South America, from southern Canada to Ecuador.
HABITAT
These turtles mainly live in permanent water bodies, ones
that are filled with water all year long. Some are able to survive
in somewhat salty waters, but they typically prefer freshwater.
Although they spend the majority of their time in the water,
they will travel quite a distance over land to nest, and one species
makes overland trips from one watering hole to another.
Snapping Turtles 33
DIET
Snapping turtles are primarily meat eaters,
dining on almost anything they can find,
whether it is alive or dead. The diet includes
worms, insects, snails, and larger items, such
as other turtles, ducklings, and small mam-
THE LURE OF THE TURTLE mals. Although it is not common, some tur-
Besides being the biggest member of the tles can live on an all-plant diet.
snapping turtle family, the alligator snapping
BEHAVIOR AND REPRODUCTION
turtle has another interesting feature. It uses
a bit of flesh on its tongue to draw in hungry Most people know snapping turtles for their
fishes. This “lure” not only looks like a pink unfriendly personality. The turtles can quickly
worm but also wiggles like a worm. When a strike out with their long necks and powerful
fish approaches to nab an easy lunch, the jaws and snap at any passing animals, whether
turtle quickly lashes out and clamps its it is a fish or other prey they want to eat or a
strong jaws around the unsuspecting fish. person who comes too close. Instead of teeth,
Besides fishes, this turtle’s diet includes they have a hook at the front of the upper jaw
snails, clams, plant roots, other turtles, birds, that helps in grasping and then tearing apart
and even small alligators. prey. Snapping turtles occasionally sunbathe,
or “bask,” on land, but more typically they float
just below the water’s surface and soak up the
warmth there. Snapping turtles that live in warmer climates are
active day and night all year long, but those that live in cooler ar-
eas usually are active only during the day and typically spend the
cold winter months buried in the muddy bottom of a waterhole.
During the breeding season, the female digs a hole on land,
sometimes near the water and at other times quite far away, in
dry areas. There, she lays up to 109 round eggs and buries them.
Snapping turtles provide no care for the eggs or the young that
hatch from the eggs. The outdoor temperature controls the
number of males and females in each batch of eggs.
SNAPPING TURTLES AND PEOPLE
Although snapping turtles are not especially friendly, they
are of little threat to humans who do not bother them. Humans
hunt the turtles for food and occasionally for the pet trade.
CONSERVATION STATUS
The World Conservation Union (IUCN) lists the alligator
snapping turtle as Vulnerable, which means that there is a high
threat of their extinction: they could die out entirely. There are
many sources for these threats, including too much hunting of
them and the loss of good habitat.
SPECIES
SNAPPING TURTLE ACCOUNT
Chelydra serpentina
Snapping Turtles 35
Habitat: These turtles typically live in plant-
filled, shallow, calm waters with mucky bottoms.
Most make their homes in freshwater areas, but
some live quite well in somewhat salty waters.
Books:
Behler, John L., and F. Wayne King. The Audubon Society Field Guide to
North American Reptiles and Amphibians. New York: Knopf, 1979.
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. London: Dorling Kindersley, 2001.
Conant, Roger, and Joseph T. Collins. A Field Guide to Reptiles and
Amphibians: Eastern and Central North America. Boston: Houghton
Mifflin, 1998.
Harding, J., and J. Holman. Michigan Turtles and Lizards: A Field Guide
and Pocket Reference. East Lansing: Michigan State University Museum,
1990.
Hickman, Pamela. Turtle Rescue: Changing the Future for Endangered
Wildlife. Richmond Hill, Ontario, Canada: Firefly Books, 2004.
O’Keefe, M. Timothy. Sea Turtles: The Watcher’s Guide. Lakeland, FL:
Larsen’s Outdoor Publishing, 1995.
Pritchard, P. C. H. The Alligator Snapping Turtle: Biology and Conservation.
Milwaukee, WI: Milwaukee Public Museum, 1989.
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians.
Boston: Houghton Mifflin, 2003.
Web sites:
“Common Snapping Turtle.” Chesapeake Bay Program. http://www
.chesapeakebay.net/info/snapping_turtle.cfm (accessed on September
14, 2004).
Snapping Turtles 37
Dillon, C. Dee. “The Common Snapping Turtle” Tortuga Gazette 34, no.
3 (March 1998): 1–4. http://www.tortoise.org/archives/snapping.html
(accessed on September 14, 2004).
LeClere, Jeff. “Snapping Turtle: Chelydra serpentine.” Iowa Herpetology.
http://www.herpnet.net/IowaHerpetology/reptiles/turtles/snapping_turtle
.html (accessed on September 14, 2004).
▲
Class: Reptilia
Order: Testudines
Family: Dermatemydidae
One species: Central American
river turtle
family C H A P T E R (Dermatemys mawii)
GEOGRAPHIC RANGE
Central American river turtles live in Mexico, Guatemala,
and Belize.
HABITAT
Although some of them may wander into somewhat salty wa-
ter, Central American river turtles live mainly in freshwater,
such as rivers and large lakes. The turtles live in the lowlands
of southern Mexico near the Gulf of Mexico. They also live in
Belize and northern Guatemala, and possibly in Honduras.
during the rainy season the lake or river can overflow onto the
shore and flood the nests. The good news is that the eggs can
survive being underwater for up to one month. The eggs need
about seven to ten months to hatch, and most hatch anytime
from late May to July, just when the rainy season starts up. As
happens with many other kinds of turtles, warmer nest
temperatures turn most Central American river turtle eggs into
female hatchlings, or newly hatched young, and cooler tem-
peratures produce males. The warm or cool weather has
to occur when the eggs are about halfway along in their
development.
CONSERVATION STATUS
Both the World Conservation Union (IUCN) and the U.S.
Fish and Wildlife Service label the Central American river tur-
tle as Endangered, or facing a very high risk of extinction in
the wild or throughout all or a significant portion of its range.
Some governments have protected these turtles, which makes
hunting or collecting them illegal.
Books:
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. United Kingdom: Dorling Kindersley, 2001.
Lee, Julian C. The Amphibians and Reptiles of the Yucatán Peninsula.
Ithaca, NY: Comstock, 1996.
Web sites:
“Family Dermatemydidae (Mesoamerican River Turtles).” http://www.
embl-heidelberg.de/uetz/families/Dermatemydidae.html (accessed on
August 7, 2004).
Lowry, H. 2001. “Dermatemys mawii.” Animal Diversity Web.
http://animaldiversity.ummz.umich.edu/site/accounts/information/
Dermatemys_mawii.html (accessed on August 7, 2004).
▲
Class: Reptilia
Order: Testudines
Family: Dermochelyidae
One species: Leatherback sea
turtle (Dermochelys
coriacea)
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The leatherback seaturtle, which is the only member of its fam-
ily, is extremely large. The carapace (KARE-a-pays), or upper
subclass
shell, measures up to 8 feet (2.4 meters) long, and the turtle it-
order self weighs just under a ton, at 1,911 pounds (867 kilograms).
monotypic order Most seaturtles have a hard and bony upper shell, but this tur-
tle’s carapace has a smooth, leathery skin. It also has an unusual
suborder outline. The upper shell is wide at the front but then narrows to
▲ family a point at the back, giving it a teardrop shape. In addition, seven
very noticeable ridges run from the front of the carapace to the
back. This shell is usually black with a few white or yellow spots—
almost as if someone had shaken a paintbrush over the back of
the turtle. The plastron (PLAS-trun), or bottom shell, has color-
ing that is the opposite of the carapace coloring. Instead of black
with light spots, it is white with dark spots. Leatherback turtles
also have large front legs, which do not have separate toes and
claws but instead look like paddles or fins.
GEOGRAPHIC RANGE
This species lives in oceans around the world.
HABITAT
The leatherback seaturtle is found over more of the world
than perhaps any other species of reptile. It can live quite well
in the warm ocean waters of the tropics and in cooler ocean
waters as far north of the equator as Alaska and Iceland and as
far south as New Zealand and the Cape of Good Hope at the
DIET
The diet of the leatherback seaturtle is
mostly jellyfish. It also eats many other SAVING LEATHERBACKS
ocean-living animals, including snails, Leatherback seaturtles have survived
octopuses, squids, crabs, small fishes, and on Earth for at least 100 million years. They
hydrozoans (hy-druh-ZOH-uhns). Hydro- have even outlasted the great dinosaurs,
zoans and jellyfish are both sea-dwelling an- yet they are now facing extinction. The
imals without a backbone that have tentacles number of female leatherbacks worldwide
(TEN-tih-kuhls), or long, thin body parts dropped from 115,000 in 1982 to fewer
used for feeling or for holding on to things. than 25,000 two decades later, and the
These two types of animals look somewhat turtles living in the Pacific Ocean suffered
alike. Seaturtles sometimes think that float- the biggest decline in numbers. Many
ing balloons and plastic bags look much like conservation groups, as well as country
these creatures too, and they eat them by governments, are worried about the future
mistake. This can kill the turtle. The turtles of this turtle and are trying to do away with
also eat plants, such as sea grasses and kelp, hunting and egg collecting. They are also
which is a type of seaweed. preserving their nesting beaches and
protecting adult turtles from fishing and
BEHAVIOR AND REPRODUCTION other activities at sea that accidentally
Like other turtles, the leatherback seatur- harm the turtles.
tle is cold-blooded, meaning that its body
temperature gets cooler when the outside
temperature drops and warmer when the outside temperature
rises. In most turtles, body temperature very closely matches
the outdoor temperature. The seaturtles are a little different.
Because they are so large and their muscles heat up when they
swim, they can stay warm much longer than a smaller turtle
can. They also have oily skin that acts like a jacket, to help
keep the body warm. For these reasons, they are able to travel
to much colder waters, like those off Alaska or Iceland. These
turtles take advantage of this ability to travel to warm and cold
waters. They often swim very long distances in what are called
migrations (my-GRAY-shuns), moving from one region or cli-
mate to another to find food and to lay their eggs. Scientists
have tracked some turtles that have swum as far as 3,100 miles
(4,989 kilometers) one way to go from a nesting site to a feed-
ing site. On average, these turtles swim about 19 miles (30.5
kilometers) a day for weeks at a time.
Leatherback Seaturtle 45
Many leatherback seaturtles may join together at a particu-
larly good feeding site, like a school, or group, of jellyfish. They
also hunt for food alone. Seaturtles are excellent divers, and
they can swim down to more than 3,300 feet (1,006 meters) to
find deep-water animals to eat. Turtles do most of their diving
at night, but they are active both day and night.
Scientists know very little about courtship or mating in
leatherback turtles. The turtles may mate before or during the
long migration from a feeding area to a nesting area or just off-
shore from the nesting site. Females make their nests about
once every three or four years on tropical beaches. Those that
live in the Atlantic Ocean nest from April to November. Pacific
Ocean leatherbacks nest at different times of the year, depend-
ing on the beach they choose. A small group of females usu-
ally nests together on one beach.
The females climb up onto shore, usually at night, and find
a spot on dry land. They typically pick a nesting site that is just
beyond the highest point that water reaches. Like the upper
shell, the lower shell of leatherbacks is softer than that of most
turtles, so the females choose sandy rather than rocky beaches
to crawl over and dig their nests. They use both their front and
back legs to dig a wide hole that can fit the entire body. Then
they continue to dig a smaller, deeper pit with just the rear legs.
Each female lays 47 to 263 eggs in the pit. Only some of the
eggs hatch. From the time she lays them, 1 to 103 eggs have
no yolks and so cannot develop into turtles. The rest are nor-
mal eggs. Eggs are round and range in diameter, or width, from
1.9 to 2.6 inches (4.8 to 6.6 centimeters) in diameter. Each egg
weighs 2.5 to 3.2 ounces (71 to 91 grams).
Usually, the biggest females lay the most eggs and the largest
eggs. In addition, turtles of the Atlantic typically lay more eggs
than those of the Pacific, and nests made during the middle of
the nesting season often contain more eggs than nests made
earlier or later. Females may make up to eleven nests a year,
although five or six is more common. Once she lays the eggs,
the female uses her hind legs to cover them with sand and then
continues with her front and rear legs to bury the larger body
hole. She then leaves the area and provides no care for the eggs
or the newly hatched young.
The eggs hatch in sixty to sixty-eight days, although some
may hatch in as little as fifty days or as much as seventy-eight
Leatherback Seaturtle 47
Leatherback seaturtle (Dermochelys coriacea)
CONSERVATION STATUS
According to the World Conservation Union (IUCN), this
species is Critically Endangered, which means it faces an ex-
tremely high risk of extinction in the wild. The U.S. Fish and
Wildlife Service lists the leatherback turtle as Endangered,
meaning that the turtle is in danger of extinction through all
or most of its range, or the region over which it roams and
feeds. The number of leatherback turtles has dropped rapidly
over a very short time, mostly due to hunting of adults
and gathering of their eggs. Development of tropical beaches
for homes and resorts is also making it more and more
difficult for the turtles to find a safe nesting spot. Many coun-
tries are now making it illegal to kill adult turtles or take
their eggs or else protecting the beaches where they lay their
eggs.
Books:
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. New York: DK Publishing, Inc., 2001.
Hickman, Pamela. Turtle Rescue: Changing the Future for Endangered
Wildlife. Richmond Hill, Canada: Firefly Books, 2004.
O’Keefe, M. Timothy. Sea Turtles: The Watcher’s Guide. Lakeland, FL:
Larsen’s Outdoor Publishing, 1995.
Pritchard, Peter C. H., and Pedro Trebbau. The Turtles of Venezuela.
Athens, OH: Society for the Study of Amphibians and Reptiles, 1984.
Watt, E. Melanie. Leatherback Turtles. Austin, TX: Raintree Steck-Vaughn
Publishers, 2002.
Web sites:
“Leatherback Sea Turtle.” In the Wild: Oceans. http://www.bagheera
.com/inthewild/van_anim_turtle.htm (accessed on September 10, 2004).
“The Leatherback Turtle.” Oceanic Resource Foundation. http://www
.orf.org/turtles_leatherback.html (accessed on September 10, 2004).
“The Leatherback Turtle (Dermochelys coriacea).” Turtle Trax.
http://www.turtles.org/leatherd.htm (accessed on September 10, 2004).
Leatherback Seaturtle 49
NEW WORLD POND
TURTLES
Emydidae
▲
Class: Reptilia
Order: Testudines
Family: Emydidae
Number of species: 35 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The New World pond turtles come in many shapes and sizes.
Adult small bog turtles have upper shells, or carapaces (KARE-
subclass
a-pays), that grow to about 5 inches (12.7 centimeters) in
order length, while the carapaces of the large Gray’s sliders can reach
monotypic order a length of 2 feet (61 centimeters) or more. Most pond turtles
have a least a little webbing between their toes. The males and
suborder females look very much alike, though sometimes the females
▲ family are larger. In some species, the male is more colorful and has
long, thin front claws.
GEOGRAPHIC RANGE
Members of this family live in North and South America,
Europe, western Asia, and northern Africa.
HABITAT
New World pond turtles may live in tropical areas, where it
feels like summer all year, or in cooler areas that have all four
seasons, including winter. These cooler areas are known as
“temperate climates.” Many turtles spend almost their entire
lives in or near ponds, lakes, and other freshwater areas, though
some can live quite well in saltier waters. Other species live
their lives mainly on land.
DIET
Depending on the species, New World pond turtles may eat
meat, plants, or a combination of meat and plants. Sometimes,
CONSERVATION STATUS
According to the World Conservation Union (IUCN), six
New World pond turtles are Endangered, meaning that they
face a very high risk of extinction in the wild. Seven species
are Vulnerable, meaning that there is a high risk that they will
become extinct in the wild, and fourteen are Near Threatened,
meaning that they are at risk of becoming threatened with ex-
tinction in the future. The U.S. Fish and Wildlife Service lists
the Alabama red-bellied turtle as Endangered and three other
species as Threatened. Pollution, collection for the pet trade,
and destruction of habitat, or the areas in which the turtles pre-
fer to live, are major reasons that the numbers of these turtles
are low. In addition, raccoons and other animals often dig up
nests and eat the turtle eggs.
SPECIES
PAINTED TURTLE ACCOUNTS
Chrysemys picta
Painted turtles and people: Most people know these turtles as the
ones they see basking on logs in lakes and rivers. Some people col-
lect the turtles for the pet trade, and a few eat their meat.
Habitat: This species lives in much of the eastern half of the United
States and parts of Mexico near the Gulf of Mexico. It is a land tur-
tle that roams forests and fields.
Diet: Eastern box turtles eat a variety of plants and animals, in-
cluding grasses, flowers, and berries as well as insects and earthworms.
Eastern box turtles and people: This turtle is popular in the pet
trade because of its size and friendly behavior. People rarely see them
live in the wild, except when the turtles attempt to cross a road—an
activity that too often results in death from a passing car.
Books:
Behler, John L., and F. Wayne King. The Audubon Society Field Guide to
North American Reptiles and Amphibians. New York: Knopf, 1979.
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. London: Dorling Kindersley, 2001.
Conant, Roger, and Joseph T. Collins. A Field Guide to Reptiles and
Amphibians: Eastern and Central North America. Boston: Houghton
Mifflin, 1998.
Dodd, C. Kenneth, Jr. North American Box Turtles: A Natural History.
Norman: University of Oklahoma Press, 2001.
Gibbons, J. Whitfield. Life History and Ecology of the Slider Turtle.
Washington, DC: Smithsonian Institution Press, 1990.
Harding, J. H. Amphibians and Reptiles of the Great Lakes Region. Ann
Arbor: University of Michigan Press, 1997.
Harding, J. H., and J. A. Holman. Michigan Turtles and Lizards. East
Lansing: Michigan State University, 1990.
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians.
Boston: Houghton Mifflin, 2003.
▲
Class: Reptilia
Order: Testudines
Family: Geoemydidae
Number of species: 62 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Eurasian pond and river turtles and neotropical wood tur-
subclass tles are small to large turtles. The upper shell, or carapace
(KARE-a-pays), is bony. Most of these turtles have webbing be-
order tween their toes. Some of them have a side-to-side hinge in the
monotypic order bottom shell, or plastron (PLAS-trun), which allows them to
close up tight if they feel threatened. In some species, the males
suborder
and females look quite different from each other. The male In-
▲ family dian tent turtle, for example, grows to only about a third of the
size of the female, which is typically 1 foot (30.5 centimeters)
long. The largest members of this family weigh 110 pounds
(50 kilograms) and have upper shells that can reach 32 inches
(81 centimeters) in length.
GEOGRAPHIC RANGE
These turtles live in Eurasia, North Africa, Mexico, and Cen-
tral and South America.
HABITAT
The members of this family live in the saltwater of the ocean’s
coastline, in inland freshwater areas, or on land in forests. They
typically are found in the tropical areas of many countries, in-
cluding China and the nations of the East Indies and Europe.
They live from northern Mexico in North America to Ecuador
and Brazil in South America. They also live in regions bordering
the tropics, which are called “subtropical” regions.
CONSERVATION STATUS
According to the World Conservation Union (IUCN) eleven
species are Vulnerable, meaning that there is a high risk that
they will become extinct in the wild. Eighteen species are En-
dangered, or facing a very high risk of extinction, and thirteen
are Critically Endangered, or facing an extremely high risk of
extinction. One species is Extinct; there is no longer any liv-
ing turtle in the species. The U.S. Fish and Wildlife Service de-
scribes the Indian sawback turtle and river terrapin as
Endangered. Turtle declines can be traced to too much col-
lecting and to loss of their habitat. Efforts are under way to
breed some of the most threatened species in captivity to in-
crease their numbers.
SPECIES
YELLOW-MARGINED BOX TURTLE ACCOUNT
Cistoclemmys flavomarginata
They sometimes travel into rice paddies and freshwater ponds and
streams. Some of them only rarely, if ever, leave the forests.
Diet: Some members of this turtle group eat only plants, some eat
only meat, and others eat both plants and meat.
Books:
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. London: Dorling Kindersley, 2001.
Liat, Lim Boo, and Indraneil Das. Turtles of Borneo and Peninsular
Malaysia. Kota Kinabalu, Malaysia: Natural History Publications (Borneo),
1999.
Zhou, J., and T. Zhou. Chinese Chelonians Illustrated. Nanjing, China:
Jiangsu Science and Technology Publishing House, 1992.
▲
Class: Reptilia
Order: Testudines
Family: Kinosternidae
Number of species: 25 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class American mud and musk turtles have glands, or sacs, along
their sides that produce a musky substance that smells like the
subclass spray of a skunk. The upper shell, or carapace (KARE-a-pays),
order is rather tall, giving each turtle the outline of half a flattened
monotypic order ball when viewed from the side. The lower shell, or plastron
(PLAS-trun), looks different in separate species. In some species
suborder the plastron has one or two hinges reaching from the left to the
▲ family right side of the shell, but in others the shell has no hinges.
The hinges allow the plastron and carapace to pull tight against
one another after the turtle pulls its head, neck, legs, and tail
into the shell. Some mud and musk turtles have a plastron that
covers only part of the lower body, while others have a quite
large plastron that almost entirely conceals the undersides.
All of these small to medium-sized turtles have barbels (BAR-
buhls), which are small bits of flesh that dangle from the chin.
A few have very large heads. Most of the species in this family
have a carapace that is less than 8 inches (20 centimeters) long
and in some cases grows to just 4 inches (10 centimeters) in
length. The largest species, called the Mexican giant musk tur-
tle, has a carapace that reaches 15 inches (38 centimeters) long.
Males and females look quite similar. Males, however, usually
have thicker and longer tails that are tipped with a spine. Males
also have two rough, scaly patches on each hind leg.
GEOGRAPHIC RANGE
Members of the American mud and musk turtle family live
in North and South America.
CONSERVATION STATUS
Most species of American mud and musk turtles are quite
common in their habitats, but according to the World Conser-
vation Union (IUCN), four species are Vulnerable, which means
they face a high risk of extinction in the wild. Three of the four
live in very small areas, and the fourth lives in a disappearing
habitat. The U.S. Fish and Wildlife Service lists one species, the
flattened musk turtle, as Threatened, or likely to become en-
dangered in the near future.
SPECIES
STINKPOT ACCOUNT
Sternotherus odoratus
Stinkpots and people: Some people collect stinkpots for the pet
trade, but this practice is not very common.
Books:
Behler, John L., and F. Wayne King. The Audubon Society Field Guide to
North American Reptiles and Amphibians. New York: Knopf, 1979.
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. London: Dorling Kindersley, 2001.
Conant, Roger, and Joseph T. Collins. A Field Guide to Reptiles and
Amphibians of Eastern and Central North America. 3rd ed. Boston:
Houghton Mifflin, 1998.
Harding, J. H., and J. A. Holman. Michigan Turtles and Lizards. East
Lansing: Michigan State University, 1990.
▲
Class: Reptilia
Order: Testudines
Family: Pelomedusidae
Number of species: 18 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class African side-necked turtles are small- to medium-sized tur-
tles that fold their necks sideways under their shells, rather than
subclass
pulling them straight back into the shell, along with their heads.
order They have five claws on each hind foot. The upper shell, or
monotypic order carapace (KARE-a-pays), of adults usually is less than 1 foot
(30.5 centimeters) long, but the length of shells can range from
suborder about 4 to 21.6 inches (10–55 centimeters). The turtle has a
▲ family large lower shell, or plastron (PLAS-trun), that covers much of
the chest and belly. Sometimes the plastron has a hinge that al-
lows the animal to pull its lower shell quite tight against the
upper shell and offers protection from predators (PREH-duh-
ters), or animals that seek these turtles out as a source of food.
In addition, the turtles have glands, or special organs, along the
sides of their bodies that give off a musky, or earthy, smell to
ward off attackers.
GEOGRAPHIC RANGE
African side-necked turtles live in Africa, Madagascar, and
the Seychelles Islands, which are northeast of Madagascar.
HABITAT
These turtles often are seen in freshwater lakes and rivers
that hold water all year long, but they also are found in tem-
porary freshwater ponds, which lose their water during the dry
season. Some side-necked turtles, including those that are called
“mud turtles,” spend much of their time in soft-bottomed ponds
that are filled with water for only a few weeks every year.
CONSERVATION STATUS
In 2003 the World Conservation Union (IUCN) listed one
species, the Seychelles mud turtle, as Extinct; none of these tur-
tles is still alive. In addition, it listed the Magdalena river tur-
tle and the Madagascar big-headed turtle as Endangered,
meaning that it faces a very high threat of extinction in the
wild. Five species are Vulnerable, which means that there is a
high threat of their extinction, and one is Near Threatened,
meaning that it is at risk of becoming threatened with extinc-
tion soon. Many of these species live in very small areas, so
even slight disturbances can kill populations and possibly the
entire species. For example, the Broadley’s mud turtle, which
is listed as Vulnerable, is found only in Lake Rudolph (also
known as Lake Turkana) in Kenya.
SPECIES
HELMETED TURTLE ACCOUNT
Pelomedusa subrufa
Books:
Boycott, R. C., and O. Bourquin. The Southern African Tortoise Book: A
Guide to Southern African Tortoises, Terrapins and Turtles. KwaZulu-
Natal, South Africa: privately printed, 2000.
Branch, B. Field Guide to the Snakes and Other Reptiles of Southern
Africa. Cape Town, South Africa: Struik Publishers, 1998.
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. London: Dorling Kindersley, 2001.
Spawls, S., K. Howell, R. Drewes, and J. Ashe. A Field Guide to the Rep-
tiles of East Africa. San Diego: Academic Press, 2002.
Web sites:
“Pelomedusa subrufa.” ETI—Turtles of the World. http://www.eti.uva.nl/
Turtles/Turtles3a.html (accessed on July 27, 2004).
▲
Class: Reptilia
Order: Testudines
Family: Platysternidae
One species: Big-headed turtle
(Platysternon
megacephalum)
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The family Platysternidae has only one member, the big-
headed turtle, which has the scientific name Platysternon mega-
subclass
cephalum. This small to medium-sized turtle is most known for
order its huge head, which is about half as wide as the upper shell.
monotypic order The head is shaped like a triangle and covered with a single,
large, hard scale, known as a scute (SCOOT). The upper shell,
suborder or carapace (KARE-a-pays), is quite flat and sometimes has a
▲ family single ridge running down the middle from front to back. The
carapace is yellow to dark-brown and may have a pattern on
it. A few big-headed turtles have red or pink markings on the
carapace. Like that of many other turtles, the lower shell, or
plastron (PLAS-trun), of the big-headed turtle is yellow and
covers most of the underside. Unlike those of many other tur-
tles, the upper and lower shells of the big-headed turtle are not
connected by a bony bridge, but by softer, more flexible tissue,
called ligaments (LIH-guh-ments). The upper jaw, also known
as the beak, comes to a sharp point in the front. The big-headed
turtle has a scaly tail that is nearly as long as the upper shell.
The feet have obvious claws and just a bit of webbing between
the toes. Turtle size is measured by the length of the carapace.
The carapace length of the big-headed turtle reaches about 8
inches (20 centimeters). Males and females are similar, but the
males have a more indented plastron.
GEOGRAPHIC RANGE
The big-headed turtle lives in China, Laos, Myanmar,
Thailand, and Vietnam.
Big-headed Turtle 77
Big-headed turtle (Platysternon megacephalum)
but also to grab onto window curtains and scramble all the way
to the ceiling. In the wild, the turtles likely put this climbing
ability to good use for crawling over rocky stream bottoms and
against fast current. Some people report seeing the turtles
climbing trees and bushes in the wild.
Big-headed turtles appear to be nocturnal (nahk-TER-nuhl)
and crepuscular (kreh-PUS-kyuh-lur) in the wild. Nocturnal
means they are active at night, and crepuscular means they are
active at dusk and dawn. During the day, these turtles take
cover and relax underwater beneath logs or rocks and wedged
into cracks in boulders. Big-headed turtles that live in colder
waters disappear in the winter. Although no one knows where
the turtles go, scientists believe they probably hibernate (HIGH-
bur-nayt), which means they enter a deep sleep. Some people
think the turtles may hibernate in a protected spot on land.
Little is known about the courtship, or mate-attracting ac-
tivities, of big-headed turtles or about their mating and nesting
behaviors. In the wild the females probably nest sometime from
May to August. The only egg ever seen hatching did so in cap-
tivity, and it hatched in September. In each clutch, or nest of
eggs, females lay one or two eggs, sometimes as many as four.
The eggs are 1.5–1.7 inches (3.8–4.3 centimeters) long and are
about 0.9 inches (2.3 centimeters) wide. The eggs are quite
large considering that the turtle’s carapace length only reaches
8 inches (20 centimeters). No one knows whether the turtle
Big-headed Turtle 79
lays one or more than one clutch a year. In captivity these tur-
tles can live to be as old as twenty-five years.
CONSERVATION STATUS
According to the World Conservation Union (IUCN) the big-
headed turtle is Endangered because of overcollection. Endan-
gered means that this species is facing a very high risk of
extinction in the wild in the near future.
Books:
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. United Kingdom: Dorling Kindersley, 2001.
Web sites:
Kirkpatrick, David T. “The Big-headed Turtle, Platysternon mega-
cephalum.” www.unc.edu/dtkirkpa/stuff/bigheads.html (accessed on
August 6, 2004).
▲
Class: Reptilia
Order: Testudines
Family: Podocnemididae
Number of species: 8 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The Afro-American river turtle is described as a “side-necked” class
turtle because it cannot pull its neck and head straight back into
subclass
the shell. Instead, it folds its neck sideways under its shell. The
largest member of this family has an upper shell, or carapace order
(KARE-a-pays), that reaches 42 inches (107 centimeters) in monotypic order
length. Afro-American river turtles have only four toes on their
hind feet. Some species also have barbells (BAR-buhls), which suborder
are bits of flesh that dangle from their chins. Some scientists be- ▲ family
lieve that these turtles should be grouped with similar turtles in
the family Pelomedusidae, which live in mainly in Africa.
GEOGRAPHIC RANGE
Afro-American river turtles are found in Madagascar and
northern South America.
HABITAT
Many of these freshwater turtles live on riverbanks and in
large lakes, but some also live in streams and swamps, wetlands
partly covered with water. Sometimes they move into flooded
forests. Their range, or the area in which they live and feed, in-
cludes Madagascar, which lies off the eastern coast of southern
Africa, and northern South America.
DIET
Afro-American river turtles are mainly plant eaters; they are
especially fond of fruits that drop off the trees on the shore and
fall into the water. They also eat stems, leaves, and grasses.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), seven
of the eight species face some threat of survival. Two species
are Endangered, meaning that there is a very high risk that they
will become extinct in the wild soon. Four species are Vulner-
able, facing a high risk of extinction. One species is listed as
Lower Risk: Conservation Dependent, meaning that its survival
depends on conservation measures. The U.S. Fish and Wildlife
Service lists two species as Endangered. Much of the decline in
this family of turtles can be traced to too much hunting of adults
and collecting of their eggs. Efforts are under way to protect
the turtles’ nesting areas, so that the females have a safe place
to lay their eggs.
SPECIES
ACCOUNT SOUTH AMERICAN RIVER TURTLE
Podocnemis expansa
Diet: This species eats plants, insects, and sponges, but it prefers
the fruits of riverside trees.
Conservation status The U.S. Fish and Wildlife Service lists this
turtle as Endangered, which means that it is facing a risk of extinc-
tion in the wild. The World Conservation Union (IUCN) lists it as
Lower Risk/Conservation Dependent, which means that its survival
relies on sound conservation efforts. These listings result from the
fact that humans have killed adults and destroyed their eggs over
many decades. The turtle’s range became smaller and smaller as the
hunting and collecting continued. Efforts are under way to protect
their nesting areas and to prevent further collecting of turtles or their
eggs. ■
Books:
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. London: Dorling Kindersley, 2001.
Web sites:
Pecor, Keith. “Pelomedusidae.” Animal Diversity Web. http://
animaldiversity.ummz.umich.edu/site/accounts/information/
Pelomedusidae.html (accessed on August 6, 2004).
▲
Class: Reptilia
Order: Testudines
Family: Testudinidae
Number of species: About 47
species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
Tortoises are small- to large-sized, land-living turtles. Most class
of them have a tall upper shell, or carapace (KARE-a-pays). Their
subclass
back legs are thick and somewhat resemble the legs of an ele-
phant. The front legs, on the other hand, are rather flat and cov- order
ered with large scales. Their toes have no webbing between monotypic order
them, and many species have five claws on each front foot. The
largest members of this family can weigh as much as 562 pounds suborder
(255 kilograms) and have upper shells that grow to 4 feet 7 ▲ family
inches (1.4 meters) long. Some of them have a hinge in the
carapace or in the lower shell, which is called the plastron
(PLAS-trun).
GEOGRAPHIC RANGE
Tortoises exist on all large islands and continents, except
Australia and Antarctica.
HABITAT
Tortoises live in many habitats, including deserts, grasslands,
shrubby areas, and forests. Most live in warmer climates in
North and South America, Europe, Asia, and Africa, and many
make their homes on large islands in the ocean.
DIET
The tortoises are mainly plant-eaters, eating everything from
grasses, flowers, and leaves to fruits and seeds. If they come
across them, a few tortoises will also eat insects, worms, or
other living or dead animals.
Tortoises 87
BEHAVIOR AND REPRODUCTION
Tortoises are known for their slow, lum-
bering movements on land. The males often
fight among themselves, either by ramming
their shells against one another or by biting
at each other’s legs. A male will also do the
TORTOISES AND BIRDS same things to a female in an attempt to con-
Galápagos tortoises have an unusual vince her to mate with him. In addition, he
relationship with small birds, known as will bob his head at her and chase her. Fe-
Darwin’s finches. Ticks and other small males lay from one to 51 eggs at a time. Each
biting insects often hitch a ride on a of the round or oblong eggs is about 1 to 2
tortoise’s skin, but the tortoise frequently inches (3 to 6 centimeters) in diameter and
cannot reach them to remove them. The is typically quite brittle, or easily broken.
birds feed on these same organisms. Some females may not nest every year, but
Darwin’s finches and Galápagos tortoises when they do, they may have more than one
seem to have struck a deal. When the clutch, or nest of eggs, per season. Although
finches fly in, the tortoises stand up as tall scientists have not tested all of the species,
as they can and stretch out their necks, so the eggs in most become males or females
the birds can pick off the insects and mites based on the temperature of the nest. A par-
from every nook and cranny on their skin. ticularly warm nest produces mostly females,
Both the birds and the tortoises benefit: and an especially cool one produces males.
The bird gets an easy meal, and the tortoise The eggs typically hatch in 100 to 160 days,
gets some needed relief. but one species’ eggs hatch only after 18
months. Some species may live 200 years or
more.
Many tortoises become inactive in the summer when the
weather is very dry. Many simply hide during the day in a shady
spot, but some will dig a hole, or burrow, and spend the hottest
part of the day there. On cooler days, some of these tortoises
will seek out a warm spot and sunbathe, or bask, to increase
their body temperature. Those species that live in colder cli-
mates may become inactive in the winter months.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), one
species is Critically Endangered or facing an extremely high risk
of extinction in the wild, seven are Endangered or facing a very
high risk of extinction in the wild, and sixteen are Vulnerable
Tortoises 89
Galápagos tortoise (Geochelone nigra)
SPECIES
ACCOUNTS GALÁPAGOS TORTOISE
Geochelone nigra
Diet: The Galápagos tortoise eats almost nothing but plants, in-
cluding grasses, cacti, fruits, and leaves.
Behavior and reproduction: Active during the day, they spend their
nights sleeping among plants or rocks. Males of this species, like the
males of some other species, fight one another by ramming their shells
together. Males do the same thing to females during mating season,
which runs from December to August. During mating, he will make
roaring noises. The female lays up to four sets, or clutches, of eggs from
late June to December. She digs a hole, drops in two to nineteen eggs,
and then buries them. She provides no other care for the eggs or young.
The round eggs measure 2.2 to 2.6 inches (56 to 65 millimeters) in
diameter. The eggs hatch eighty-five to two hundred days later.
Galápagos tortoises and people: Rarely collected for its food, this
tortoise has become a prized tourist attraction on the Galápagos Islands.
Tortoises 91
Desert tortoise (Gopherus agassizii)
DESERT TORTOISE
Gopherus agassizii
Diet: The desert tortoise eats mostly plants, including grasses, cacti,
and flowers.
Desert tortoises and people: People hunt these tortoises for their
meat, which is often shipped to Asian food markets located in the
western United States.
Tortoises 93
a high risk of extinction in the wild. The U.S. Fish and Wildlife Ser-
vice lists the tortoise as Threatened, or likely to become endangered
in the foreseeable future. The danger to the tortoises comes from both
loss of their habitat and a dangerous bacterial infection. ■
Books
Ballasina, D., ed. Red Data Book on Mediterranean Chelonians. Bologna,
Italy: Edagricole, 1995.
Burnie, David, and Don E. Wilson, eds. Animal: The Definitive Visual
Guide to the World’s Wildlife. United Kingdom: DK Publishing Inc., 2001.
Pritchard, Peter C. H., and Pedro Trebbau. The Turtles of Venezuela.
Athens, OH: Society for the Study of Amphibians and Reptiles; Oxford,
OH, 1984.
▲
Class: Reptilia
Order: Testudines
Family: Trionychidae
Number of species: 25 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
From above, softshell turtles look almost like rubber dinner class
plates swimming through the water. Although the turtles ac-
subclass
tually have a bony upper shell, it is completely covered by leath-
ery skin, which usually reaches out past the edge of the bone order
and overlaps the tail and feet. The upper shell, or carapace monotypic order
(KARE-a-pays), is flat and often round. The turtles also have a
tube-like snout and a long neck that they can pull in or extend suborder
out. Their webbed front feet each have three claws. A few ▲ family
species have flap-like hinges on the lower shell, or plastron
(PLAS-trun), below the hind legs. Softshell turtles can be big
or small, depending on the species. The smallest has a carapace
that only measures up to 5 inches (12 centimeters) long, while
the largest has a carapace ten times that length and sometimes
more. In addition, most of them have a one-color carapace, but
a few have stripes or spots. Sometimes, young turtles are more
colorful. Usually, the males have longer tails than the females
do. In some species, the males are smaller than the females,
and/or more colorful.
GEOGRAPHIC RANGE
Members of this family live in North America, Africa, and Asia.
HABITAT
These water-loving turtles live in all types of year-round fresh
water, occasionally in ponds that dry up for part of the year. A
few can swim into somewhat salty water for a brief time, but
only one species, the Asian giant softshell, actually lives in the
Softshell Turtles 95
saltier waters of the coast. Overall, members
of this family live east of the Rocky Moun-
tains in North America and in mainly warmer
climates in northern Africa, southern Asia,
and the Indo-Australian archipelago, which
is near Australia. They have also been intro-
FLAPS FOR PROTECTION duced elsewhere, including Hawaii.
Some species of softshell turtles have
DIET
flaps near the hind legs that they can use
to shield themselves from the glaring sun Most of these turtles are almost completely
during dry spells. One species, called the meat-eaters, and they eat anything they hap-
Indian flapshell turtle, buries itself in the pen to come across, whether it is alive or
mud, pulls its legs inside its shell, covers dead. Once in a while, they will eat plants.
up the hind legs with the flaps, and stays A few species hunt by ambush, which means
inside the shell in a state of deep sleep that the softshell turtle waits in hiding
until the rains come. This period of deep underwater — usually buried just under the
sleep, which can last up to 160 days in this bottom — for a fish or other water-living an-
turtle, is called estivation (es-tih-VAY-shun). imal to swim by and then juts out its long
Estivation is similar to the inactive period neck and quickly grabs it with its mouth.
known as hibernation (high-bur-NAY-shun),
but hibernation occurs over the wintertime. BEHAVIOR AND REPRODUCTION
For the most part, these turtles remain
hidden for much of the day. They fall to the
bottom of the lake, pond, or other watering hole where they
live and wiggle their bodies back and forth until they are buried.
When they move about in the water, they are excellent swim-
mers. Many species sunbathe, or bask, to warm their bodies.
Some spend several hours a day basking on logs that stick up
out of the water or on the shoreline, but they typically dash
back into the water at even the slightest disturbance. Some pre-
fer to sunbathe by simply floating in the top layer of water.
They can breathe through the nose, but they can also get oxy-
gen directly from the water, so they can stay below the surface
for long periods of time. Those that live in colder areas enter
a state of deep sleep, or hibernation (high-bur-NAY-shun), in
the winter. During this period, which may last several months,
they bury themselves in the sand or mud at the water bottom
to wait for spring and warmer temperatures to come.
Softshell turtles usually mate each spring, although females
can actually mate one year and have young from that single
mating for several years. In some species, the male attracts the
female by rubbing his chin on her carapace and bobbing his
CONSERVATION STATUS
According to the World Conservation Union (IUCN), more
than half of the family’s 25 species are at risk. Five species are
Critically Endangered, which means that they are facing an ex-
tremely high risk of extinction in the wild. In addition, five are
Endangered and face a very high risk of extinction in the wild,
and six are Vulnerable and at high risk of extinction in the wild.
The U.S. Fish and Wildlife Service also lists four non-U.S.
species as Endangered, or in danger of extinction throughout
all or a significant portion of their range. Softshells are coping
with overhunting, polluted waters that can weaken and/or kill
the animals, and loss of their habitat.
Softshell Turtles 97
Spiny softshell (Apalone spinifera)
SPECIES
ACCOUNT SPINY SOFTSHELL
Apalone spinifera
Diet: Spiny softshells mostly eat meat in the form of just about any-
thing they can find, including crayfish, fishes, and insects that live in
the water. They will also eat acorns and leaves.
Softshell Turtles 99
the spiny softshell can stay underwater for long periods without
drowning. Those that live in colder areas hibernate from fall to spring
by burying themselves in the mud or sand beneath the water and re-
maining inactive.
Spiny softshells mate in the spring in deep waters. Scientists know
little about their courtship or mating behaviors. In June and July, the
female crawls on shore and then quickly digs a hole, drops the eggs
inside, and covers it up. She provides no additional care for the eggs
or the young turtles. She may lay two clutches a year. Each clutch con-
tains four to thirty-two round eggs, each of which measures about 1.1
inches (2.8 centimeters) in diameter. They hatch in about fifty-five to
eighty-five days. When the males reach four to five years old and the
females reach eight to ten years old, they are ready to mate and be-
come parents themselves. They live to be fifty years old or more.
Spiny softshells and people: People hunt this turtle for food, ei-
ther to eat themselves or to ship overseas to meat markets in Asia.
Some people also collect spiny softshells for the pet trade.
Books
Behler, John L., and F. Wayne King. The Audubon Society Field Guide to
North American Reptiles and Amphibians. New York: Knopf, 1979.
Conant, Roger, and Joseph T. Collins. A Field Guide to Reptiles and
Amphibians of Eastern and Central North America, Third Edition Ex-
panded. Boston: Houghton Mifflin Co., 1998.
Harding, J. H., and J. A. Holman. Michigan Turtles and Lizards. East
Lansing: Michigan State University Press, 1990.
Stebbins, Robert C. A Field Guide to Western Reptiles and Amphibians.
Boston: Houghton Mifflin Co., 1985.
●
Class: Reptilia
Order: Crocodylia
Number of families: 3 families
order C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The order Crocodylia, also known as the crocodilians, in- class
cludes 23 species of the most feared and most fascinating ani-
subclass
mals on the planet. They include 14 species of crocodiles and
false gharials in the family Crocodylidae; eight species of alli- ● order
gators and caimans in the family Alligatoridae; and one species monotypic order
of gharial (GUR-ee-ul) in the family Gavialidae.
suborder
The crocodilians look somewhat like large lizards, but with
thick and scaly skin, exceptionally strong tails, and large teeth- family
filled jaws. The scales on the upper surface, including the back
and top of the tail, are large and rectangular in shape and have
bony plates, called osteoderms (OSS-tee-oh-durms), just under
the surface. Rows of these scales, which often have knobs or
ridges, run from the rear of the head to the tail. On the legs
and the sides of the body, the scales are smaller. Belly scales,
which may also contain osteoderms, are large and smooth.
Crocodilian tails are usually about as long as or a bit longer
than the body, and in some species, like the Nile crocodile, the
tails have a tall ridge of scales down the center.
The jaws contain large teeth, many of which show outside
the mouth even when it is closed. People often describe the
“grin” of a crocodilian. Of course, the animals are not actually
smiling, but a slight upturn in the back of the jaw line of most
species makes them look as if they are. Most, but not all, croc-
odilians have wide jaws. The Indian gharial is one species with-
out a wide jaw. Instead, it has a very long and exceptionally thin
pair of jaws filled with razor-sharp teeth. The false gharial, which
GEOGRAPHIC RANGE
Most members of the family Alligatoridae live in Central
America, Mexico, the southeastern United States, and South
America. One species, the Chinese alligator, makes its home in
eastern China. The Indian gharial, the lone species in the fam-
ily Gavialidae, lives in scattered places within India, Nepal, and
Pakistan and rarely Bangladesh and Bhutan. The crocodiles and
false gharials in the family Crocodylidae live over the largest
area of the three families. At least one species lives in Africa,
Asia, Australia, North America, and South America.
HABITAT
Most crocodilians live in tropical or subtropical regions. The
American alligator, which can be found in the United States as
far north as North Carolina, and the Chinese alligator live in
the coolest climates of all the crocodilians and sometimes have
to survive freezing temperatures. These two species spend the
coldest parts of the year in underground burrows, in deep wa-
ter, or lying in shallow water with just the nose poking above
the sometimes ice-covered water surface.
Alligators, caimans, and gharials need freshwater habitat, but
crocodiles and false gharials can survive in freshwater or salt-
water. Crocodiles usually stay out of the open oceans, however,
and instead make their homes in saltwater marshes or creeks.
Books:
Alderton, D. Crocodiles and Alligators of the World. New York: Facts on
File, 1991.
Behler, J. L., and D. A. Behler. Alligators and Crocodiles. Stillwater, MN:
Voyager Press, 1998.
Periodicals:
Barr, Alice. “Supercroc.” National Geographic World. January–February
2001, page 8.
Grant, Phoebe. “A Peep at the Alligator’s Mound.” Monkeyshines on
America. June 1990, page 19.
Perkins, Sid. “Fossils Indicate . . . Wow, What a Croc!” Science News.
October 27, 2001, volume 160, page 260.
Zackowitz, Margaret. “Dangerous Business: Photographing Crocodiles
and Hippos is a Creative Challenge.” National Geographic for Kids.
November 2001, page 26.
Web sites:
“All About Alligators.” Enchanted Learning. http://www.enchantedlearning
.com/subjects/Alligator.shtml (accessed on September 21, 2004).
“Alligator.” Everglades National Park. http://www.nps.gov/ever/eco/
gator.htm (accessed on September 21, 2004).
“Alligator.” World Almanac for Kids. http://www.worldalmanacforkids
.com/explore/animals/alligator.html (accessed on September 21, 2004).
“Alligators and Crocodiles.” San Diego Zoo. http://www.sandiegozoo.org/
animalbytes/t-crocodile.html (accessed on September 21, 2004).
“American Crocodile.” Kids’ Planet, Defenders of Wildlife. http://www
.kidsplanet.org/factsheets/american_crocodile.html (accessed on Sep-
tember 21, 2004).
“Fathers and Sons.” Florida Museum of Natural History. http://www
.flmnh.ufl.edu/cnhc/potm-oct00.html (accessed on September 21, 2004).
“Gharial.” Smithsonian National Zoological Park. http://nationalzoo.si.edu/
Animals/ReptilesAmphibians/Facts/FactSheets/ Gharial.cfm (accessed on
September 21, 2004).
“Nile Crocodiles.” National Geographic. http://www.nationalgeographic
.com/kids/creature_feature/0107/crocodiles2.html (accessed on Sep-
tember 21, 2004).
▲
Class: Reptilia
Order: Crocodylia
Family: Gavialidae
One species: Gharial
(Gavialis gangeticus)
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The lone species of gharial (GAR-ee-ul), also sometimes
subclass known as a gavial, looks much like a crocodile or alligator ex-
cept that a gharial has an extremely long and thin snout. The
order narrow jaws in both males and females are lined with more than
monotypic order 100 pinpoint-sharp teeth. The back of a gharial is covered with
tough scales, but these scales are not lumpy as they are in many
suborder
alligator and crocodile species. Gharial scales are very smooth.
▲ family Adults are dark brown or greenish brown on top and yellowish
white to white below. Young gharials have dark bands on the
body and tail. Adults also have bands, but they fade and become
less noticeable as the animal gets older. The name gharial comes
from the round knob that forms on the tip of the adult male’s
snout above the nostrils. This knob is called a ghara, because it
looks somewhat like an Indian pot of the same name.
Gharials are large reptiles. Males usually grow to 13 to 15
feet (4 to 4.5 meters) long and 350 to 400 pounds (181 kilo-
grams), although some can reach nearly 20 feet (6.1 meters).
Females are a bit smaller, usually reaching 11.5 to 13 feet (3.5
to 4 meters) in length. They have long and powerful tails. They
are so strong that the gharial need only sway its tail side to side
to glide through the water. While swimming, it usually holds
its legs back and alongside the body and does not move them.
People sometimes confuse the gharial with the false gharial.
Both are large animals with a similar shape. The false gharial,
also known as the Malayan gharial, has a long and thin snout,
but it is not quite as long and thin as that of the true gharial.
DIET
As youngsters, gharials eat tadpoles, shrimp, insects, and fish
they find in the water. As they get older, they become more se-
lective and will eat almost nothing but fish. They usually hunt
by ambush, which means that they remain completely still and
wait for a fish to swim close. At that point, their unusual teeth
become useful. At the front of the lower jaw, a gharial’s teeth
face outward at such an angle that the tip of the mouth when
it is closed looks like a pin cushion. As the fish nears, the ghar-
ial snaps its jaws sideways at the prey and stabs it with these
very sharp teeth. With a upward jerk of its head, the reptile
flings the fish off of its teeth and into the back of its mouth.
Gharial 109
BEHAVIOR AND REPRODUCTION
Like some of the other alligators and crocodiles, gharials usu-
ally get along quite well and live together in groups. They stay
in the water most of the time, coming out occasionally to bask
on shore. While they are excellent swimmers, they are slow on
land and must drag their bellies and tails on the ground when
they walk. They rarely wander too far from the water’s edge and,
at the slightest threat, will dive back into the safety of the river.
On especially warm days, they may open their mouths wide to
cool off. This serves the same purpose as panting does for a dog.
When mating season arrives in December and January, the
adult males begin fighting one another to set up and defend
territories in shallow water. Their fights look something like
wrestling matches. Two males lie side by side, lift their heads
out of the water, and begin pushing each other with their
snouts. The winner is the one that can topple over the other.
Sometimes, the wrestling matches become more violent, and
the two males hit each other with their snouts or bite each
other. A male with a good territory may be able to attract sev-
eral large females to mate with him. Scientists also believe that
the size of the male’s ghara may also be important during the
mating season. The males can use the ghara to produce a loud
buzz, which may be attractive to females. Males also will buzz
to warn other males to stay away.
After mating, a female will lay her eggs sometime from March
to May. She crawls up a steep bank at the riverside and begins
looking for a spot for her nest. She digs her nest in dry ground
at least 5 feet (1.5 meters) above water level. A female gharial
is very fussy about her nest and may change her mind several
times, even after starting to dig, before settling on the perfect
place to lay her eggs. The female becomes territorial and guards
her specific nest sites from other females, although she will
share the beach with many other females and their nests. After
digging a hole in the sand, she lays her eggs inside and care-
fully covers them. The smallest females lay as few as a dozen
eggs, and many first-time mothers lay eggs that never hatch at
all. The largest females, on the other hand, may lay almost 100
eggs. A typical gharial egg is 2.2 inches (5.5 centimeters) wide,
3.4 inches (8.6 centimeters) long, and weighs 5.5 ounces (156
grams). Females remain near their nests and will defend them
from predators, if necessary. The eggs hatch 53 to 92 days later,
with nests in warmest climates hatching out earliest and babies
in the coolest areas breaking out of their eggs last. The tem-
perature of the nest also controls the number of males and fe-
males. Especially warm nests produce more males, and cooler
ones produce more females.
The mother gharial helps her young out of the nest, and then
she and possibly the father watch over them. Despite this care,
many of a female’s young do not survive. Numerous animals,
including pigs, hyenas, monitor lizards, and some humans, are
fond of gharial eggs, while some birds and turtles often gobble
up babies. In addition, the babies are born during the monsoon
season and often drown in the floods that are common at this
time of year. Of those that do survive, the females are ready to
mate when they reach about 10 feet (3 meters) long and are at
least 8 years old. The males can mate once they are 15 years
old and about 11.5 feet (3.5 meters) long.
CONSERVATION STATUS
The World Conservation Union (IUCN) and the U.S. Fish
and Wildlife Service consider this species to be Endangered,
Gharial 111
Gharial (Gavialis gangeticus)
Books:
Daniel, J. C. The Book of Indian Reptiles and Amphibians. New Delhi, In-
dia: Oxford University Press, 2002.
Ross, C. A., ed. Crocodiles and Alligators. New York: Facts on File Inc.,
1989.
Rue, Leonard Lee. Alligators and Crocodiles. Wigston, Leicester: Magna
Books, 1994.
Gharial 113
ALLIGATORS
AND CAIMANS
Alligatoridae
▲
Class: Reptilia
Order: Crocodylia
Suborder: Eusuchia
Family: Alligatoridae
Number of species: 8 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Like crocodiles, the alligators and caimans have a heavy body,
with the back and tail covered by armor-like scales. Crocodiles,
subclass
alligators, and caimans have a strong tail, which is at least as
order long as the rest of the body, and the back half of the tail often
monotypic order has a row of tall, ridged scales along the top. They also have a
long snout, hind limbs larger than the front legs, and large, pow-
suborder erful jaws filled with teeth. Alligators and crocodiles are, how-
▲ family ever, different. All of an alligator’s or caiman’s lower teeth are
hidden when its mouth is closed. In crocodiles, one lower tooth
remains outside the jaw, even when it is clamped shut.
When alligators are young, they often have dark bands on
their bodies, but these disappear as they get older. Adults may
be dark gray, brown, black, or a bit yellowish. The smallest
species is Cuvier’s dwarf caiman, which grows to about 4 feet
(1.2 meters). The largest is the American alligator, which can
reach 13 feet (4 meters) long.
GEOGRAPHIC RANGE
Depending on the species, alligators and caimans may live
in Central America, Mexico, the southeastern United States,
South America, and/or eastern China.
HABITAT
Alligators and caimans are freshwater species that prefer still
or slow-moving water, even if it is muddy or murky. Besides
lakes, rivers, and streams, they are often found in swamps,
CONSERVATION STATUS
The World Conservation Union (IUCN) considers the Chi-
nese alligator to be Critically Endangered, which means that it
faces an extremely high risk of extinction in the wild. It also
lists the black caiman as Conservation Dependent, which means
it still requires attention to make sure it survives. The U.S. Fish
and Wildlife Service lists the American alligator, a U.S. species,
as Threatened, or likely to become endangered in the foresee-
able future. These and other alligators and caimans often suffer
from habitat loss and overhunting, and numerous conservation
efforts are under way to protect them.
SPECIES
AMERICAN ALLIGATOR ACCOUNTS
Alligator mississippiensis
Diet: Meat-eaters, they will dine on almost any animal they come
across, including turtles, fishes, mammals, and sometimes smaller al-
ligators. They swallow most smaller prey whole. For larger animals,
however, the alligators first drown the victim, then chomp off mouth-
fuls of flesh.
COMMON CAIMAN
Caiman crocodilus
Books:
Lamar, William. The World’s Most Spectacular Reptiles and Amphibians.
Tampa, FL: World Publications, 1997.
Web sites:
“All About Alligators.” Enchanted Learning. http://www.enchantedlearning
.com/subjects/Alligator.shtml (accessed on September 21, 2004).
“Alligator.” Everglades National Park. http://www.nps.gov/ever/eco/
gator.htm (accessed on September 21, 2004).
“Alligator.” World Almanac for Kids. http://www.worldalmanacforkids
.com/explore/animals/alligator.html (accessed on September 21,
2004).
“Alligator mississippiensis (DAUDIN, 1801).” Florida Museum of Natural
History. http://www.flmnh.ufl.edu/cnhc/csp_amis.htm (accessed on
December 15, 2004).
“Alligators and Crocodiles.” San Diego Zoo. http://www.sandiegozoo
.org/animalbytes/t-crocodile.html (accessed on September 21, 2004).
“Crocodilian Species List.” Florida Museum of Natural History. http://
www.flmnh.ufl.edu/cnhc/csl.html (accessed on December 15, 2004).
“The Reptiles: Alligators and Crocodiles.” Nature. http://www.pbs.org/
wnet/nature/reptiles/ (accessed on December 15, 2004).
“Spectacled Caiman.” Enchanted Learning. http://www.enchantedlearning
.com/subjects/reptiles/caiman/Speccaiman.shtml (accessed on Septem-
ber 21, 2004).
“Wild Things: The Not-So-Friendly Caiman.” Kidzworld. http://www
.kidzworld.com/site/p483.htm (accessed on September 21, 2004).
▲
Class: Reptilia
Order: Crocodylia
Family: Crocodylidae
Number of species: 14 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
Fourteen species of crocodiles make up this family, includ- class
ing one called a false gharial. (An Indian gharial also exists, but
subclass
it is not a crocodile and is instead listed in its own separate
family.) The crocodiles are medium to large reptiles, with adults order
ranging from about 5 feet (1.5 meters) long in the smallest monotypic order
species to 20 feet (6.1 meters) long in the largest. Within
species, females are smaller overall. For example, female John- suborder
stone’s crocodiles typically grow to 5 feet (1.5 meters), while ▲ family
the average male is about 6.5 feet (2 meters) long. In all species,
the tail is about as long as the rest of the body.
Crocodiles, alligators, and caimans are often confused be-
cause they all have armor-like scales on the back and tail, a
powerful tail, a pair of back legs that are stronger and larger
than the front pair, and toes that are webbed on the back pair
of feet and unwebbed on the front pair. Perhaps most notice-
ably, they also all share a long snout filled with teeth. Croco-
diles, however, have something the others lack. Counting from
the front of the mouth, the large fourth tooth on each side of
a crocodile’s lower jaw shows outside of the mouth when the
jaw is closed. In other species, this large tooth is hidden, al-
though many other teeth on the upper jaw may be visible when
the mouth is clamped shut.
GEOGRAPHIC RANGE
At least one species of crocodiles lives in each of these conti-
nents: Africa, Asia, Australia, North America, and South America.
DIET
Crocodiles are meat-eaters that shift from eating insects and
spiders as youngsters to larger and larger animals as they grow.
Adults of the largest crocodiles, like the Nile crocodile, eat an-
imals as big as warthogs, cows, and sometimes humans. They
are skilled hunters that sneak up on prey by ever so slowly
swimming closer and closer, and then lunging out with mouth
open to clamp down on the surprised animal. This method of
sneaking up on prey is called stalking. Once the jaw snaps shut,
the prey has little chance of escaping. With a captured mam-
mal, the crocodile typically pulls it underwater, and when the
animal drowns, tears off chunks to swallow. Crocodiles also
hunt for prey by ambush, which means that they stay still in
the water and wait for a prey animal to happen by. Besides live
meals, crocodiles will also eat the dead animals they find.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), nine
of the 14 species are at risk. This includes three listed as Crit-
ically Endangered, which means they face an extremely high
risk of extinction in the wild; two as Endangered and facing a
very high risk of extinction in the wild; three species as Vul-
nerable and under a high risk of extinction in the wild; and one
as Conservation Dependent, which means it could be at risk if
conservation efforts ceased. In addition, the IUCN describes
one species as Data Deficient, which means that scientists have
too little information to make a judgment about its threat of
extinction. The U.S. Fish and Wildlife Service lists 12 of the 14
species as Threatened, or likely to become endangered in the
foreseeable future, or Endangered, which means they are in
danger of extinction throughout all or a significant portion of
their range. Most of the species are at risk because of habitat
loss and overhunting. Several efforts are now under way to help
protect these animals.
SPECIES
AMERICAN CROCODILE ACCOUNTS
Crocodylus acutus
Diet: Young American crocodiles catch and eat insects, tadpoles and
frogs, crabs, and fish, and then switch to larger prey as they grow.
Adults are able to feed on animals as large as cows and, in very rare
cases, humans.
NILE CROCODILE
Crocodylus niloticus
Diet: The adult diet is mostly fish, although Nile crocodiles will also
eat large mammals, such as warthogs and antelopes.
Books:
Cleaver, Andrew. Snakes and Reptiles: A Portrait of the Animal World.
Wigston, Leicester: Magna Books, 1994.
Daniel, J. C. The Book of Indian Reptiles and Amphibians. New Delhi,
India: Oxford University Press, 2002.
Irwin, Steve, and Terri Irwin. The Crocodile Hunter. New York: Penguin
Putnam, 1997.
Lamar, William. The World’s Most Spectacular Reptiles and Amphibians.
Tampa, FL: World Publications, 1997.
Ross, C. A., ed. Crocodiles and Alligators. New York: Facts on File, Inc.,
1989.
Rue, Leonard Lee. Alligators and Crocodiles. Wigston, Leicester: Magna
Books, 1994.
Schmidt, K. P. A Check List of North American Amphibians and Reptiles.
Chicago: University of Chicago Press, 1953.
Smith, H. M., and E. H. Taylor. An Annotated Checklist and Key to the
Reptiles of Mexico Exclusive of Snakes. Washington, DC: Bulletin of the
U.S. National Museum, 1950.
Webb, G. J. W., and S. C. Manolis. Crocodiles of Australia. New South
Wales, Australia: Reed Books Pty, Ltd., 1989.
Web sites:
“Crocodilian Species List.” Florida Museum of Natural History.
http://www.flmnh.ufl.edu/cnhc/csl.html (accessed on December 15,
2004).
“Crocodylus niloticus (LAURENTI, 1768).” Florida Museum of Natural
History. http://www.flmnh.ufl.edu/cnhc/csp_cnil.htm (accessed on
December 15, 2004).
“The Reptiles: Alligators and Crocodiles.” Nature. http://www.pbs.org/
wnet/nature/reptiles/ (accessed on December 15, 2004).
●
Class: Reptilia
▲
Order: Sphenodontia
Family: Sphenodontidae
Number of species: 2 species
monotypic order
C H A P T E R
GEOGRAPHIC RANGE
Tuataras have a small range, living on about 30 tiny and
hard-to-reach islands off New Zealand’s shore.
HABITAT
Although neither species is widespread, the northern tuataras
make their homes over a bigger area than the Brother Islands tu-
ataras. The northern tuataras live on 26 islands off northeastern
North Island and on four islands of Cook Strait off the northern
coast of South Island. The Brother Islands tuatara lives only on
North Brother Island in Cook Strait. Both species are burrowers
and live in shady forests where the trees grow thick enough to
block the sun almost completely from reaching the ground.
DIET
Usually active at night, the tuataras often hunt by ambush,
which means that they sit still and wait for a prey animal to
come to them. They also forage (FOR-ej), which means that
they wander about looking for food. They use their sticky fat
tongues to catch and eat mainly non-flying grasshoppers, bee-
tles, and other crawling invertebrates (in-VER-teh-brehts),
which are animals without backbones. The unusual arrange-
ment of their teeth is not only excellent for crushing inverte-
brates but is also well-suited to the occasional meal of a seabird,
lizard, or perhaps a smaller tuatara. The younger tuataras are
more likely than the adults to hunt during the daytime. This
practice may help them avoid being eaten by adult tuataras.
Tuatara 133
crowded, sometimes with tuatara burrows
less than 3 feet (0.9 meters) apart. In some
cases, 810 tuataras may share a single acre of
land (2,000 per hectare). They get along
quite well, but males will fight one another
for small territories, where they hope to at-
A VERY OLD REPTILE tract females for mating. The battles begin
The tuatara is the only descendant of an with two males lining up next to each other,
ancient group of reptiles that were with each facing in the opposite direction.
common in the late Triassic and Jurassic They then puff up the throat, stiffen the crest
periods about 180 to 220 million years spines on the back so they stand on end, open
ago. At that time, they were spread out over wide the mouth, and snap the jaws shut tight.
Europe, Africa, and North America. They Usually this display is enough for one of the
started to disappear during the dinosaurs’ two males to surrender and leave the area.
reign, and almost all of them were Occasionally, however, neither one retreats,
completely gone by the early Cretaceous and the two males engage in biting matches.
Period, which followed the Jurassic. A tiny
Females mate once every two to five years,
group, however, survived on a piece of land
but males mate every year. Males set up their
that broke off the mainland and eventually
territories in summer and fall and begin do-
formed the islands of New Zealand. This
group of animals, called a lineage (LIN-ee-
ing what is called a “proud walk” to catch a
ej) because it connects species through female’s eye. Doing some of the displays he
time to their ancestors, gave rise to the two does when battling males, he tries to attract
current-day tuatara species. a female by slowly strutting around her while
stiffening his back crest and puffing up his
throat. If she is interested, she stays. If not,
she simply walks away. After mating, a female must wait until
the following spring to lay her eggs. Most lay four to 13 eggs,
but the larger northern tuataras from Cook Strait often lay eight
to 15. Each female makes a hole that may be very shallow or
up to 20 inches (50 centimeters) deep, lays her eggs, and cov-
ers them loosely with dirt. The eggs do not hatch until 12 to
15 months later. As in many other reptiles, the temperature of
the nest controls whether the eggs hatch into males or females.
In the case of the Brother Islands tuatara, warmer nests pro-
duce mostly males, and cooler ones produce mostly females.
Tuataras cannot mate until they are up to 13 years old. They
live to be at least 60 and possibly much longer.
CONSERVATION STATUS
The World Conservation Union (IUCN) considers the
Brother Islands tuatara to be Vulnerable, which means that it
faces a high risk of extinction in the wild. The U.S. Fish and
Wildlife Service lists both species as Endangered or in danger
of extinction throughout all or a significant portion of their
range. One of the greatest threats to the tuataras comes from
introduced species, especially rats, which attack and kill the
reptiles. Several programs are under way to remove the rats and
to prevent any other predators from reaching the islands; these
efforts are helping the tuataras to make a comeback. In addi-
tion, other programs are helping to return tuataras to those
places where they once lived but had disappeared.
Tuatara 135
Northern Tuatara (Sphenodon punctatus)
SPECIES
ACCOUNT NORTHERN TUATARA
Sphenodon punctatus
Books:
Tesar, Jenny. What on Earth is a Tuatara? Woodbridge, CT: Blackbirch
Press, 1994.
Periodicals:
“Quick Bits: Tuatara.” Ranger Rick. August 1999, vol. 33, page 12.
“Tuataras ‘The Living Fossil’ Explained.” Monkeyshines on Health &
Science. Spring 1998, page 14.
Web sites:
Musico, B. “Sphenodon punctatus.” Animal Diversity Web. http://
animaldiversity.ummz.umich.edu/site/accounts/information/Sphenodon_
punctatus.html (accessed on December 20, 2004).
“The Tuatara.” Kiwi Conservation Club. http://www.kcc.org.nz/animals/
tuatara.asp (accessed on December 20, 2004).
Tuatara 137
“Tuatara.” San Diego Zoo. http://www.sandiegozoo.org/animalbytes/
t-tuatara.html (accessed on December 20, 2004).
“What Can You Tell Me About Tuatara?” Museum of New Zealand Te Papa
Tongarewa. http://www.tepapa.govt.nz/TePapa/English/CollectionsAnd
Research/FAQs/FAQs_NaturalEnvironment.htm#tuatara (accessed on
December 20, 2004).
●
Class: Reptilia
Order: Squamata
Number of families: About 42
families
order C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The 7,200 species of snakes, lizards, and wormlizards all fall class
under the order Squamata and are therefore known as squa-
subclass
mates (SKWAH-mates). Perhaps the most noticeable difference
between the snakes and the lizards are the legs, or the lack of ● order
them. Most lizards, except for a few species, have working legs. monotypic order
Snakes are legless. The most noticeable feature of the worm
lizards is their earthworm-like body. While they have scales suborder
and earthworms do not, worm lizards’ scales are arranged in family
rings and separated with grooves to give them the appearance
of an earthworm’s ringed body. Most of the worm lizards are
legless, although a few have two front legs just behind the head.
Besides smelling with their noses and tasting with their
tongues, most squamates also smell with a special organ on the
roof of their mouths. They use it by first flicking or otherwise
picking up chemicals on the tongue. They then place the tongue
on the roof of the mouth at what is called the Jacobson’s or-
gan, which smells the chemicals. For hearing, many lizards have
ears that are visible as a hole on either side of the head. Nei-
ther the snakes nor the wormlizards have the openings for their
ears. Scientists believe that snakes can probably only hear very
low-pitched sounds, including ground vibrations that they
sense in the jaw and send to the ear.
In addition to the presence or absence of ear holes, known
as external ears, snakes and lizards have another obvious dif-
ference. The majority of lizards have eyelids that close and
open. Snakes, on the other hand, have a spectacle over their
GEOGRAPHIC RANGE
Besides the Arctic, Antarctic, and other very cold places,
squamates live almost the world over.
HABITAT
Squamates can live in many habitats, from the dry condi-
tions in the desert to the wet and warm rainforests. Many of
them, including numerous lizards and snakes, live above
ground on land. Some, such as the wormlizards, are fossorial
(foss-OR-ee-ul), which means that they remain underground
most of the time. Others, including many snakes, are arboreal
(ar-BOR-ee-ul), which means that they often live above the
ground among tree branches. Some, like the water snakes,
rarely leave their freshwater streams or ponds, while the sea
kraits are snakes that spend their lives in salt water.
CONSERVATION STATUS
The World Conservation Union (IUCN) lists 265 species as
being at risk or as already extinct, which means they are no
longer in existence. Of these, 14 are Extinct, 36 are Critically
Endangered, and 31 are Endangered. Critically Endangered
means the species faces an extremely high risk of extinction in
the wild. Endangered means the species faces a very high risk
of extinction in the wild. Many of these species have been hurt
by habitat loss or by the introduction of new species, especially
predators, to their habitat.
Books:
Badger. D. Lizards: A Natural History of Some Uncommon Creatures —
Extraordinary Chameleons, Iguanas, Geckos, and More Stillwater, MN:
Voyageur Press, 2002.
Cleaver, Andrew. Snakes and Reptiles: A Portrait of the Animal World.
Wigston, Leicester: Magna Books, 1994.
Greene, Harry W. Snakes: The Evolution of Mystery in Nature. Berkeley:
University of California Press, 1997.
Lamar, William. The World’s Most Spectacular Reptiles and Amphibians.
Tampa, FL: World Publications, 1997.
Mattison, Chris. Lizards of the World. New York: Facts on File, 1989.
Mattison, Chris. The Encyclopedia of Snakes. New York: DK Publishing,
1997.
McCarthy, Colin. Eyewitness: Reptile. New York: DK Publishing, 2000.
Montgomery, Sy. The Snake Scientist (Scientists in the Field). Boston:
Houghton Mifflin, 2001.
O’Shea, Mark, and Tim Halliday. Smithsonian Handbooks: Reptiles and
Amphibians (Smithsonian Handbooks). New York: DK Publishing, 2002.
Pianka, E. R. Ecology and Natural History of Desert Lizards: Analyses of
the Ecological Niche and Community Structure. Princeton, NJ: Princeton
University Press, 1986.
Pianka, E. R., and L. J. Vitt. Lizards: Windows to the Evolution of Diversity.
Berkeley: University of California Press, 2003.
Web sites:
“About Snakes.” Ohio Public Library Information Network. http://www
.oplin.lib.oh.us/snake/about/snakes.html (accessed on December 13,
2004).
“Herpetology Program.” Savannah River Ecology Laboratory. http://www
.uga.edu/srelherp/ (accessed on December 13, 2004).
Myers, P. 2001. “Reptilia.” Animal Diversity Web. http://animaldiversity
.ummz.umich.edu/site/accounts/information/Reptilia.html (accessed on
December 13, 2004).
“Reptiles.” San Diego Natural History Museum. http://www.sdnhm
.org/exhibits/reptiles/reptiles.html (accessed on December 13, 2004).
▲
Class: Reptilia
Order: Squamata
Family: Agamidae
Number of species: About 420
family C H A P T E R species
Agamids can be rather plain, or they can look quite strange class
and unusual. Their bodies may have crests, or ridges of large subclass
spines, on the back and tail. They may have neck frills and folds order
and body decorations, such as lumps and spines on the head.
Some agamids have dewlaps, or throat fans. monotypic order
suborder
Agamids come in many colors. Some are gray, brown, or
black, but they may also have more showy colors. The Thai wa- ▲ family
ter dragon is bright green with golden eyes. The rainbow lizard
is yellow or orange on top and blue on the bottom. Some
species, or types, can change color rapidly, depending on their
mood. Their lengths range from 10 inches (25.4 centimeters)
to 36 inches (91.4 centimeters). In many species, males look
different from females. They often have brighter colors, espe-
cially during the mating season, and bigger body parts, such as
heads. All agamids have four well-developed limbs, or legs.
There are usually five toes on each foot.
CONSERVATION STATUS
Most agamids are not threatened. The World Conservation
Union (IUCN) labels two species as Endangered, meaning that
they face a very high risk of extinction in the wild. One species
is listed as Near Threatened, meaning that it might soon face
serious threats. Habitat loss, or loss of their preferred living
area, is a major problem for agamids. The introduction of new
predators, such as cats and rats, to their living areas has also
harmed them.
SPECIES
ACCOUNTS SPINY AGAMA
Agama hispida
Spiny agamas and people: Spiny agamas do not interact with peo-
ple. There is a popular belief that these lizards climb trees to look
skyward to see if it will rain.
FRILLED LIZARD
Chlamydosaurus kingii
Behavior and reproduction: The frilled lizard spends most of its time
on tree trunks and low branches. It is active during the day and comes
down to the ground after it rains and to search for food. When it is
threatened or alarmed, the frilled lizard quickly enlarges the big, red-
dish-orange, fanlike frill around its neck. This frill can enlarge to a
size of 8 to 12 inches across (20.3 to 30.5 centimeters). The frill has
zigzag edges and red, blue, and brown spots. At rest, the folded frill
helps keep the lizard cool. It also acts as camouflage (KA-mah-flahzh),
a sort of disguise, allowing the lizard to look like a branch or bark.
If a predator threatens, at first the frilled lizard may hide, become
absolutely still, or run to the nearest tree. If cornered, the frilled lizard
faces the predator. It enlarges its frill and opens it brightly colored
mouth. Sometimes it hisses, stands up on its hind legs, or leaps at the
predator. If these actions do not work, frilled lizards can run on their
hind legs for short distances.
Frilled lizards mate during the wet season. Males are territorial,
protecting their living area. They may use their frills to attract mates.
Females lay a clutch or group of eight to fourteen eggs twice a year,
in spring and summer. Nests are made in flat, sandy soil, surrounded
by thin grass and leaf litter. They are not covered.
Frilled lizards and people: Frilled lizards are the reptile emblem of
Australia. They are shown on the Australian two-cent coin. There are
FLYING LIZARD
Draco volans
Books:
Barrett, Norman S. Dragons and Lizards. Danbury, CT: Franklin Watts,
1991.
Capula, Massimo. Guide to Reptiles and Amphibians of the World. New
York: Simon & Schuster, 1989.
Mattison, Chris. Lizards of the World. New York: Facts on File, 1989.
Miller, Jake. The Bearded Dragon New York: PowerKids Press, 2003.
Robinson, Fay, and Jean Day Zallinger. Amazing Lizards New York:
Scholastic, 1999.
Uchiyama, Ryu. Reptiles and Amphibians. San Francisco: Chronicle
Books, 1999.
Zoffer, David. Agamid Lizards: Keeping and Breeding Them in Captivity.
Neptune City, NJ: T. F. H. Publications, 1996.
Web sites:
“Agamids of the Cederberg.” Cape Nature Conservation. http://www
.capenature.org.za/cederbergproject/html/agamids.html (accessed on
August 12, 2004).
“Chlamydosaurus kingii (Frillneck Lizard).” Animal Diversity Web. http://
animaldiversity.ummz.umich.edu/site/accounts/information/Chlamy-
dosaurus_kingii.html (accessed on August 12, 2004).
“Common Flying Dragon.” www.wildherps.com. http:/www.wildherps.com/
species/D.volans.html (accessed on August 14, 2004).
“Rainbow Lizard.” America Zoo. http://www.americazoo.com/goto/index/
reptiles/102.htm (accessed on August 12, 2004).
▲
Class: Reptilia
Order: Squamata
Family: Chamaeleonidae
Number of species: 180 species
and
subspecies
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Chameleons (kuh-MEEL-yuns) are best known for their abil-
ity to change colors easily. Once, color change was thought to
subclass
serve as camouflage (KA-mah-flahzh), or a sort of disguise, al-
order lowing the chameleon to match or blend in to its surroundings.
monotypic order Scientists now believe that colors change in response to differ-
ences in temperature, light, and the chameleon’s mood. Colors
suborder may change in both males and females or only in males, de-
▲ family pending on the species, or type, of chameleon. Some species
can change color only into shades of brown. Others have a
wider color range, turning from pink to blue or green to red.
Varieties of color may be displayed on different body parts, such
as the throat, head, or legs. When the chameleon is excited,
stripes or patterns may appear. Sleeping or ill chameleons tend
to be pale.
Chameleons range in length from 1 inch (2.5 centimeters)
to 26.8 inches (68 centimeters). Males may be larger or smaller
than females. A chameleon’s body is flexible (FLEK-suh-buhl),
meaning that it can bend easily. It can be rather flat from side
to side and shaped somewhat like a leaf. This allows it to blend
better with leafy surroundings. A chameleon can also make its
body look longer, to seem more a part of a twig. If it is threat-
ened by a predator (PREH-duh-ter), or an animal that hunts it
for food, the chameleon can inflate, or puff up, its lungs and
make its rib cage expand, to appear larger.
Chameleons have long, slim legs, with four feet. There are
five toes on each foot. The toes are fused, or joined, in bundles
Chameleons 157
GEOGRAPHIC RANGE
Chameleons are found mainly in Madagascar and Africa, and
a few species live in southern Europe, Asia, the Seychelles and
the Comoros. No chameleons are native to the Americas, which
means that all of them were brought into the Americas. One
species is now found there in the wild.
HABITAT
Chameleons live in a variety of habitats, such as dry deserts;
tropical, rainy woodlands of evergreens; forests with trees that
lose their leaves in winter; thorn forests; grasslands; scrublands,
or land with low bushes and trees; and cloud forests, or wet,
tropical, mountain forests. They can be found from sea level
up to mountainous areas as high as 15,000 feet (4,572 meters).
DIET
Chameleons eat a variety of flying and crawling insects, in-
cluding butterflies; insect larvae (LAR-vee), or young; and
snails. The larger chameleons eat birds, smaller chameleons,
lizards, and sometimes snakes. Chameleons also eat plant mat-
ter, including leaves, flowers, and fruits. Some chameleons stay
within small areas for their food supply, but others travel long
distances seeking food. All chameleons need drinking water,
which they get from dew or rain.
CONSERVATION STATUS
The World Conservation Union (IUCN) lists four chameleon
species as Vulnerable, meaning that they face a high risk of ex-
tinction in the wild. One is Endangered, meaning that it faces
a very high risk of extinction in the near future, and one is Crit-
ically Endangered, meaning that it faces an extremely high risk
of extinction.
Chameleons 159
Jackson’s chameleon (Chamaeleo jacksonii)
SPECIES
ACCOUNTS JACKSON’S CHAMELEON
Chamaeleo jacksonii
Habitat: Jackson’s chameleon lives in areas with warm days and cool
nights, including moist forests, crop plantations, and dense bushes.
Chameleons 161
Armored chameleon (Brookesia perarmata)
ARMORED CHAMELEON
Brookesia perarmata
Chameleons 163
Common chameleon (Chamaeleo chamaeleon)
COMMON CHAMELEON
Chamaeleo chamaeleon
Books:
Bartlett, Richard D., and Patricia Bartlett. Jackson’s and Veiled
Chameleons. Hauppauge, NY: Barron’s Educational Series, 2001.
Darling, Kathy, and Tara Darling. Chameleons: On Location. New York:
HarperCollins, 1997.
Mara, W. P. Chameleons: Exotic Lizards. Mankato, MN: Capstone Press,
1996.
Chameleons 165
Miller, Jake. The Chameleon: Lizard Library. New York: PowerKids Press,
2003.
Schmidt, W., K. Tamm, and E. Wallikewitz. Chameleons: Basic Domestic
Reptile and Amphibian Library. Broomall, PA: Chelsea House Publishers,
1998.
Stefoff, Rebecca. Chameleon. New York: Benchmark Books, 1996.
Uchiyama, Ryu. Reptiles and Amphibians. San Francisco: Chronicle
Books, 1999.
Periodicals:
Cooper, Sharon Katz. “Chameleons and Other Quick- Change Artists.”
National Geographic Explorer (October 2002): 4–7.
“Chameleons’ Emotional Signals.” National Geographic (August 1993):
Earth Almanac.
“Panther Chameleons.” Ranger Rick (February 1998): 5–9.
Risley, T. “Chameleon Profile: Brookesia and Rampholeon. Chameleon
Information Network 31 (Spring 1999): 21–23.
Risley, T. “The Fate of Wild-Caught Chameleons Exported for the Pet
Trade.” Chameleon Information Network 42 (Winter 2001): 15–18.
Web sites:
Fry, Michael. “Introduction.” Chameleon Information Network. http://
www.animalarkshelter.org/cin/ (accessed on July 29, 2004).
Heying, Heather. “Family Chamaeleonidae.” Animal Diversity Web.
http://animaldiversity.ummz.umich.edu/site/accounts/information/
Chamaeleonidae.html (accessed on July 28, 2004).
Mayell, Hillary. “Evolutionary Oddities: Duck Sex Organs, Lizard Tongue.”
National Geographic News. http://news.nationalgeographic.com/news/
2001/10/1023_corkscrewduck.html (accessed on July 29, 2004).
Raxworthy, Christopher J. “A Truly Bizarre Lizard.” Madagascar—A World
Apart. http://www.pbs.org/edens/madagascar/creature3.htm (accessed
on July 29, 2004).
“Veiled Chameleon.” Reptiles & Amphibians: Smithsonian National
Zoological Park. http://national http://nationalzoo.si.edu/Animals/
ReptilesAmphibians/Facts/FactSheets/Veiledchameleon.cfm (accessed
on July 29, 2004).
▲
Class: Reptilia
Order: Squamata
Family: Iguanidae
Number of species: About 900
species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
Iguanids (ee-GWA-nids) range in size from 4 to 72 inches class
(10 centimeters to 2 meters). They have many different body
subclass
types. There are, for example, the squat, toadlike horned lizards
small enough to fit in the palm of a hand; the slim, long-tailed order
anoles (uh-NOH-lees); and the large marine iguanas. A typical monotypic order
iguanid has a long tail and four legs, with five-clawed toes on
each leg. Some have body colors or body patterns that match suborder
their surroundings. They may display bright colors during the ▲ family
mating season. Some iguanids have scales, throat fans, crests
along the back, and fringes on the toes. Certain iguanids have
the ability to lose the tail or part of the tail, to distract or fool
a predator (PREH-duh-ter), an animal that hunts them for food.
Their teeth are placed in grooves within the jaw, rather than
in sockets, or holes.
GEOGRAPHIC RANGE
Iguanid lizards are found in North America, Central Amer-
ica, South America, Fiji, the Galápagos Islands, Madagascar,
and the West Indies.
HABITAT
Iguanids live in a variety of habitats. They usually are ter-
restrial, living on land. A few are arboreal, living in trees. Many
prefer arid, or dry, areas. These desert dwellers often seek ter-
ritories, or home areas, with at least some vegetation, rocks, or
other cover to provide escape routes from predators, or animals
DIET
THIS LIZARD WALKS ON WATER Iguanids feed on insects, spiders, and
smaller lizards. A few species, such as the
Brown basilisk lizards are sometimes
desert iguana and the chuckwalla, eat leaves,
called “Jesus” lizards. When escaping a
fruits, and flowers. The marine lizard eats
predator, they may appear to walk upright
(AL-jee), plantlike organisms that live
on water. These lizards have a fringe of
mainly in water.
scales on their hind toes. These fringes
temporarily trap a bubble of air beneath the
lizards’ feet, which keeps them from BEHAVIOR AND REPRODUCTION
sinking if they run quickly enough across Iguanids are cold-blooded, which means
ponds or streams. that their body temperature varies with the
outside weather. At night, when it is cool,
many species sleep in burrows. In the morn-
ing, iguanids emerge from their burrows and rest in the sun to
warm up. They are often seen stretched out on a rock. It is nec-
essary for them to raise their body temperature to prepare for
the day’s activities of feeding, perhaps breeding, and escaping
ever-present predators. All iguanids are diurnal (die-UR-nuhl),
meaning that they are active during the daytime. If the tem-
perature grows too warm, these lizards find a shady spot so that
they do not become overheated.
Iguanids have many predators, among them, snakes, birds,
cats, rats, and wild dogs. When a predator approaches, some
species remain still and blend into the surroundings. Others are
quick runners and dash off almost immediately. They hide un-
der rocks or between thick leaves and bury themselves in sand.
A few species use special tactics to avoid their predators. The
common chuckwalla fixes itself into a crack between rocks and
then puffs up, making itself nearly impossible to remove.
Horned lizards puff up too, which makes their spines stand up
even higher. Biting predators will avoid the sharp spines. The
zebra-tailed lizard keeps changing direction when it runs, as a
way to confuse its pursuer. Other lizards squirm under the sand,
so they cannot be seen.
Iguanids have lively mating behavior. Body movements in-
clude head bobbing, pushups, and open-mouth displays. Some
species inflate their chests and throats and extend their dewlaps,
CONSERVATION STATUS
The World Conservation Union (IUCN) lists two types of
iguanids as Extinct, meaning that none remains alive. Six
species are Critically Endangered, which means that they face
an extremely high risk of extinction in the wild. Four species
are Endangered, which means that they are less endangered but
still face a very high risk of extinction. These ten species might
soon disappear from Earth. Twelve iguanids are Vulnerable,
that is, they face threats that put them at high risk of extinc-
tion and they could vanish unless they are protected. One
iguanid is Near Threatened, meaning that there is a risk that
they will be threatened with extinction. There is not enough
information to judge the status of seventeen other species. At-
tempts are being made to gather the eggs of endangered and
threatened iguanids from the wild and raise the young in pro-
tected sites, such as zoos.
SPECIES
ACCOUNTS CAPE SPINYTAIL IGUANA
Ctenosaura hemilopha
Diet: Cape spinytail iguanas eat flowers, fruits, and leaves. They feed
only during the day.
Cape spinytail iguanas and people: These iguanas are sold in the
pet trade.
COMMON CHUCKWALLA
Sauromalus obesus
Chuckwallas and people: Chuckwallas are sold in the pet trade and
sometimes are eaten as food.
GREEN ANOLE
Anolis carolinensis
Geographic range: The green anole is the only anole that inhabits
the United States. These anoles are also found in Cuba and on
Caribbean islands.
Books:
Arnosky, Jim. All about Lizards. New York: Scholastic, 2004.
Bartlett, Richard D., and Patricia Pope Bartlett. Lizard Care from A to Z.
Hauppauge, NY: Barron’s Educational Series, 1997.
Bartlett, Richard D., and Patricia Bartlett. Anoles: Facts & Advice on Care
and Breeding. Hauppauge, NY: Barron’s Educational Series, 2001.
Behler, John L. The Audubon Society Field Guide to North American
Reptiles and Amphibians. New York: Alfred A. Knopf, 1979.
Claybourne, Anna. The Secret World of Lizards. Chicago: Raintree
Publishers, 2003.
Conant, R., J. T. Collins, I. H. Conant, T. R. Johnson, and S. L. Collins.
A Field Guide to Reptiles & Amphibians of Eastern & Central North
America. Boston: Houghton Mifflin, 1998.
Periodicals:
“Amazing Lizards!” National Geographic (March 1978): 8–11.
“Color These Animals before They Change.” National Geographic (March
1980): 10–15.
Hazen-Hammond, S. “Horny Toads Enjoy a Special Place in Western
Hearts.” Smithsonian 25 (1994): 82–86.
Hughes, Catherine D. “Where Am I?” National Geographic Kids (July/
August 2004): 32–35.
“Iguanas.” Ranger Rick (August 1996): 8–9.
“Marine Iguanas.” Ranger Rick (November 2003): 18–20.
“Shrinking Iguanas.” National Geographic (September 2000).
Web sites:
“Anoles.” Melissa Kaplan’s Herp Care Collection. http://www.anapsid
.org/anole.html (accessed on July 31, 2004).
“Glossary of Iguana Terms.” Green Iguana Society. http://www
.greenigsociety.org/glossary.htm (accessed on August 3, 2004).
“Green Anole.” Texas Parks and Wildlife. http://www.tpwd.state.tx.us/
nature/wild/reptiles/anole/ (accessed on July 31, 2004).
“Green Anole Care Sheet.” AOL Hometown. http://members.aol.com/
Mite37/TPFGA.html (accessed on July 31, 2004).
“Marine Iguanas.” Galápagos Geology on the Web. http://www.geo.cornell
.edu/geology/GalápagosWWW/MarineIguanas.html (accessed on August
3, 2004).
▲
Class: Reptilia
Order: Squamata
Family: Gekkonidae
Number of species: 1,109 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
Geckos range in size from 0.67 inch (17 millimeters) to 14 class
inches (35.6 centimeters) in length. The smallest gecko weighs
subclass
about 0.07 ounce (1.98 grams). The largest gecko, which lives
in rainforests, can weigh up to 1.5 pounds (680 grams). While order
most geckos are brown, gray, or black, a few are yellow, red, monotypic order
blue, orange, or green. They may be plain, or they may have
stripes or spots. Colors on the head and neck may be different suborder
from the colors on the back. The nocturnal geckos, or those ▲ family
that are active at night, are plainer than the diurnal (die-UR-
nuhl) geckos, or those active in the daytime, which tend to
have brighter colors.
Geckos usually have flattened bodies and four short limbs,
or legs. Each limb has five toes. Some species have claws on
each foot. Other types of geckoes have widened toe pads. These
toe pads are made to allow the gecko to stick to smooth sur-
faces. Geckos have large eyes that are open all the time. Except
for a few species, the eyes do not have movable eyelids. Instead,
the eyes are protected by clear, see-through scales, or thin coat-
ings. Geckos clean these scales regularly with their long
tongues. Most geckos are nocturnal. These geckos have verti-
cal pupils (PYU-puhls), meaning that they are positioned
straight up and down, in the center of their eyes. Diurnal geckos
have round pupils in the center of their eyes. Pupils are parts
of the eye that allow light to enter.
Gecko skin is soft and loose and typically covered with gran-
ular, or grainy, scales that do not overlap. A few species have
GEOGRAPHIC RANGE
Pygopods are found in Australia and New Guinea. Geckos
are found in the tropics and subtropics, the warmer areas of
the world. These areas include India, Nepal, Burma, the
Malaysian peninsula, China, the Philippines, Indonesia, New
Zealand, Saudi Arabia, Central America, and South America.
Geckos and skinks are often the only land reptiles on remote
islands in the ocean. A few gecko species have been found in
southern Europe, southern Siberia, and the southwestern
United States.
HABITAT
Geckos live in a variety of habitats. Their preferred living ar-
eas include coniferous forests, with pine and other evergreen
trees, and deciduous forests, where trees, such as maples, lose
their leaves each year. They also live in rainforests, tropical
forests that get at least 100 inches of rain per year; this type of
forest has many very tall evergreen trees that form a thick um-
brella of leaves and branches overhead. Geckos also live in
deserts and in grassland, or meadows. Pygopods live in desert
and in grassland.
DIET
Nearly all geckos eat insects and spiders. A few larger species
eat small snakes, small lizards, and baby birds. In some habi-
tats, geckos also eat plant pollen and ripe fruit. Smaller py-
gopods are insect eaters, and larger ones eat snakes and lizards.
CONSERVATION STATUS
The conservation status of most species is unknown. Because
of illegal pet trade collection, the World Conservation Union
(IUCN) lists one brightly colored group of geckos as Endan-
gered and internationally protected.
SPECIES
WESTERN BANDED GECKO ACCOUNTS
Coleonyx variegatus
HOUSE GECKO
Hemidactylus frenatus
Books:
Bartlett, Richard D. Geckos: In Search of Reptiles and Amphibians. New
York: E. J. Brill, 1988.
Periodicals
“At Home in the Rocks, a New Gecko Emerges.” National Geographic
(June 1997): Geographica.
“Barking Gecko.” National Geographic (October 1989): 26–29.
“Fat-Tailed Gecko.” Ranger Rick (May 1994): 14–15.
“Leopard Gecko.” Ranger Rick (November 1994): 4–7.
“Where’d the Gecko Go?” National Geographic World (July 1985): 38.
Web sites
Autumn, Kellar. “Gecko Story.” http://www.lclark.edu/autumn/dept/
geckostory.html (accessed on August 8, 2004).
Muir, Hazel. “Minute Gecko Matches Smallest Living Reptile Record.”
NewScientist.com. December 3, 2001. http://www.newscientist.com/
news/news.jsp?id=ns99991635&lpos;=related_article2 (accessed on
August 9, 2004).
Schweitzer, Sophia. “Guardian Geckos.” Coffee Times. http://www
.coffeetimes.com/geckos.htm (accessed on August 9, 2004).
▲
Class: Reptilia
Order: Squamata
Family: Dibamidae
Number of species: 15 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Blindskinks (also called “blind lizards,” “blind skinks,” “leg-
less lizards,” and “wormlizards”) are small to medium-sized
subclass
lizards with a slim, snakelike form. They are fewer than 10
order inches (25.4 centimeters) long. Their body colors range from
monotypic order pale pink to light brown, with the under area, or belly, some-
times a bit paler. Their bodies are covered with shiny, smooth,
suborder and squarish overlapping scales. The scales on the head are
▲ family large and platelike, especially on the snout, or nose area, and
lower jaws.
The heads of these reptiles are blunt, not pointed. The
bones of the skull are fused, or firmly joined together. This
makes the head area very solid, which helps in burrowing,
or digging holes. Their tiny eyes look like dark specks and
have no lids. The eyes are hidden under a head scale that
does not move. The nostrils, or nose openings, are small and
placed at the tip of the snout. These lizards have no ear open-
ings that can be seen. Their ears are covered with scales.
There are only a few lower teeth, set in sockets, or hollow
openings. The teeth are small and pointed, curving backward.
The tongue is short and wide and is not divided at the tip.
The tip of the tongue does not retract, or pull back, com-
pletely.
The tails of blindskinks are very short and blunt. They are
able to break off at various places to deter predators (PREH-
duh-ters), or animals that hunt the blindskink for food. Blind-
skinks do not have any working limbs, or legs. Males have
DIET
Blindskinks feed on tiny insects, such as ants and termites
and possibly spiders.
Blindskinks 187
A blindskink on the forest floor
in Vietnam. (Robert W. Murphy.
Reproduced by permission.)
CONSERVATION STATUS
Blindskinks are not threatened. Many species suffer from loss
of their habitat, or their preferred living area, as the result of
movements of people, farming, tree removal, and pollution, or
poison, waste, or other material that makes the environment
dirty and harmful to health. There are no conservation efforts
under way to protect blindskinks.
Blindskinks 189
WORMLIZARDS
Amphisbaenidae
▲
Class: Reptilia
Order: Squamata
Suborder: Amphisbaenia
Family: Amphisbaenidae
Number of species: 160 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The members of this family, known simply as wormlizards,
subclass are long, thin, legless animals. Their scales are arranged in rings
around the body with each ring separated from the next by a
order shallow groove. This ring and groove pattern makes them look
monotypic order much like earthworms, even though the worms lack scales. In
suborder some species of wormlizard, the head is round. In others, it
may be shaped like a shovel, or in some cases the snout may
▲ family come to a point. They have no openings for their ears, as the
lizards do, and they have only the smallest of eyes showing be-
low a see-through scale, if they are visible at all. They have no
legs, but all species in this family have tiny bits of hip bones
inside their bodies. They do not, however, have a sternum
(STER-num), which is the bone at the front of the chest that
in most animal species connects to the ribs.
Most wormlizards reach about 10 to 16 inches (25 to 40 cen-
timeters) long as adults, but some species are much smaller or
much larger. The smallest species lives in Africa and only grows
to 4 inches (10 centimeters) long, while the largest, known as
the white-bellied wormlizard, can reach more than 32 inches
(80 centimeters). A wormlizard’s tail, which can look much like
the rest of the body, actually starts at the vent, a slit-like open-
ing on the underside of the animal. The tails in these animals
are very short, usually less than one-tenth of the overall body
length. The tails may be rounded, pointed at the end, or have a
flattened shape. Many of the 160 species of wormlizards have
about the same color: pale pink or pale orange-pink, sometimes
GEOGRAPHIC RANGE
Wormlizards live in both the western and eastern hemi-
spheres, including South America, Central America, the West
Indies, Africa, Asia, and Europe. They tend to live in tropical
areas or in spots with a slightly less warm, subtropical climate.
HABITAT
Wormlizards stay out of sight most of the time, either re-
maining in their burrows or beneath rocks or leaf litter on the
ground. Some of them make themselves at home in the nests
Wormlizards 191
of ants or termites, possibly even laying their eggs or having
their young there. They will come out on the surface after par-
ticularly heavy rains that flood their underground homes.
DIET
Wild wormlizards eat mainly ants, termites, beetles, grubs
(young beetles), caterpillars, and cockroaches. In one study,
scientists looked inside the stomachs of wormlizards and found
that some were filled with fungi. In another study, they found
one wormlizard that had eaten a lizard, or at least its leg, and
another that had swallowed a burrowing snake—whole. In cap-
tivity, wormlizards will eat other large vertebrates (VER-teh-
brehts), which are animals with backbones, so some people
believe they may do the same in the wild.
CONSERVATION STATUS
None of these species is considered endangered or threatened.
Wormlizards 193
White-bellied wormlizard (Amphisbaena alba)
SPECIES
ACCOUNT WHITE-BELLIED WORMLIZARD
Amphisbaena alba
Diet: With its strong jaws, the white-bellied wormlizard can eat ani-
mals as large as mice and rats in a scientist’s laboratory. In the wild,
however, they are known only to eat smaller animals, such as ants, ter-
mites, crickets, and other insects, as well as spiders and other inverte-
brates (in-VER-teh-brehts), which are animals without backbones.
Wormlizards 195
FOR MORE INFORMATION
Books:
Gans, C. Biomechanics: An Approach to Vertebrate Biology. Philadelphia:
J. B. Lippincott Company, 1974.
Halliday, Tim, and Kraig Adler, eds. The Encyclopedia of Reptiles and
Amphibians. New York: Facts on File, 1986.
Mattison, Chris. Lizards of the World. New York: Facts on File, 1989.
Schwenk, K. “Feeding in Lepidosaurs.” In Feeding: Form, Function, and
Evolution in Tetrapod Vertebrates. San Diego: Academic Press, 2000.
Vanzolini, P. E. Evolution, Adaptation and Distribution of the Amphisbaenid
Lizards (Sauria: Amphisbaenidae). Ph.D. diss. Harvard University, 1951.
Web sites:
“Amphisbaenidae.” Innvista. http://www.innvista.com/science/zoology/
reptiles/amphisba.htm (accessed on December 9, 2004).
“Family Amphisbaenidae.” Animal Diversity Web. University of Michigan
Museum of Zoology. http://animaldiversity.ummz.umich.edu/site/
accounts/classification/Amphisbaenidae.html (accessed on December
1, 2004).
“The Keeping and Maintenance of Amphisbaenians.” Cyberlizard (UK).
http://www.nafcon.dircon.co.uk/amphisb1.html (accessed on Decem-
ber 1, 2004).
“The ReptiPage: Amphisbaenia.” The ReptiPage. http://reptilis.net/
amphisbaenia/overview.html html (accessed on December 9, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Amphisbaenia
Family: Bipedidae
Number of species: 3 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The three species of mole-limbed wormlizards in this fam- class
ily are sometimes confused with earthworms, but they have subclass
scales and front legs. They are one of four families that fall into
the group known as wormlizards or amphisbaenians (am-fizz- order
BAY-nee-ens). In all amphisbaenians, small rectangular scales monotypic order
form circular rings around their long thin bodies. A worm has
rings around its body, too, but it has no scales and lacks most suborder
of the other features of wormlizards. Mole-limbed wormlizards, ▲ family
like other amphisbaenians, have one large tooth in the middle
of the upper jaw, a thick and strong skull, small and sometimes
invisible eyes, and a forked tongue. They do not, however, have
ear holes or eyelids, like most lizards do. The mole-limbed
wormlizards are different from other wormlizards, because they
have a pair of small but strong front legs right behind the short
rounded head. In addition, one of their clawed fingers has an
extra bony piece, compared to the fingers of other reptiles.
Mole-limbed wormlizards use their strong front legs, and prob-
ably this extra finger bone, to help them dig. Some scientists
believe that, because the mole-limbed wormlizards have front
legs, they are probably the most primitive of all the amphis-
baenians. Other scientists disagree. These questions will no
doubt continue, since no one has yet found a single fossil of
any member of this family. Although mole-limbed wormlizards
do not have hind legs, the skeleton still has some bits of hip
bone and a tiny nub of thigh bone.
Mole-limbed wormlizards grow to 4.5 to 9.4 inches (11.5 to
24 centimeters) long and at the middle of the body are about
CONSERVATION STATUS
Scientists still have much to learn about these animals; how-
ever, they are not now considered endangered or threatened.
SPECIES
ACCOUNT TWO-LEGGED WORMLIZARD
Bipes biporus
Geographic range: It makes its home along the western side of the
Baja California peninsula in Mexico.
Diet: They search underground for ants, termites, and the larvae
(LAR-vee) of insects to eat. Larvae are newly hatched insects that usu-
ally have soft bodies. Grubs, for example, are the larvae of beetles. At
night, they also look for food, including insects and spiders, above
ground.
Books:
Burnie, David, and Don Wilson, eds. The Definitive Visual Guide to the
World’s Wildlife. New York: DK Publishing, 2001.
Gans, C. Biomechanics: An Approach to Vertebrate Biology. Philadelphia:
J. B. Lippincott Company, 1974.
Halliday, Tim, and Kraig Adler, eds. The Encyclopedia of Reptiles and
Amphibians. New York: Facts on File, 1986.
Mattison, Chris. Lizards of the World. New York: Facts on File, 1989.
Schwenk, K. Feeding: Form, Function, and Evolution in Tetrapod Verte-
brates. San Diego: Academic Press, 2000.
Vanzolini, P. E. Evolution, Adaptation and Distribution of the Amphisbaenid
Lizards (Sauria: Amphisbaenidae). Ph.D. diss. Harvard University, 1951.
Web sites:
“Family Bipedidae (two-legged worm lizards).” Animal Diversity Web. Uni-
versity of Michigan Museum of Zoology. http://animaldiversity.ummz
.umich.edu/site/accounts/classification/Bipedidae.html (accessed on
December 1, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Amphisbaenia
Family: Rhineuridae
One species: Florida worm lizard
(Rhineura floridana)
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
Florida wormlizards, the only living species in this family, class
are long and thin creatures without legs. They have thin rings subclass
circling their round bodies, no ear openings, and usually no
visible eyes. This combination of features makes many people order
confuse them with earthworms. Florida wormlizards, however, monotypic order
have scales, and worms do not. In fact, it is the scales on the
suborder
wormlizard’s head that cover its eyes. The head is hard and
somewhat flattened with a bladelike front edge, which helps ▲ family
the lizard to dig into the soil. The upper jaw sticks out farther
than the lower jaw, so the animal has an overbite of sorts. The
shape of the head has caused some people to call them shov-
elnose wormlizards. They are usually a pearly pinkish white
color, but some individuals may be tinted slightly orange-pink.
Their heads and tail tips are sometimes a bit darker. Like most
snakes, they shed their skin—actually just the top layer of
skin—in one piece.
Adults can grow to about one-half inch (1.2 centimeters)
around at the middle of the body and reach 9.5 to 11 inches (24
to 28 centimeters) long, including a short tail. The tail begins
at the vent, a slit-like opening on the underside of the animal,
and is only about one-tenth of the total length of the worm-
lizard. The tail, which is slightly flattened, is covered on top
with little cone-shaped bumps called tubercles (TOO-ber-kuls).
Inside the body, Florida wormlizards look much like
other types of wormlizards, which are all grouped together
under the name amphisbaenians (am-fizz-BAY-nee-ens). The
GEOGRAPHIC RANGE
Once thought to live only in north-central and northeastern
Florida, scientists now know that it also exists in southern
Georgia.
HABITAT
Florida wormlizards make their homes in the sandy and loose
but rich soil of usually dry pine and broad-leaved forests. They
DIET
Scientists are unsure exactly what Florida
wormlizards eat, but they believe they proba-
bly eat the same things that other amphisbae-
nians eat. Most amphisbaenians travel through
their underground burrows looking for and
dining on the ants, termites, and grubs that Florida wormlizards stay
they find there. The Florida wormlizards flick their forked underground most of the time.
tongues to pick up chemicals in the air and on the ground. (©Dave Norris/Photo
Researchers, Inc. Reproduced by
They then press the tongue on the roof of the mouth, where a permission.)
special organ, called a Jacobson’s organ, lies. This organ “tastes”
the chemicals to tell the wormlizard about the prey animals
that might be nearby. They also use their special ear set-ups to
“hear” even very faint vibrations in the ground. This super-
hearing ability probably helps the wormlizards to hear move-
ments made by even very small insects and therefore makes
them especially good hunters.
CONSERVATION STATUS
This species is not considered endangered or threatened.
Books:
Behler, John, and F. Wayne King. “Worm Lizard (Rhineura floridana).”
National Audubon Society Field Guide to Reptiles and Amphibians. New
York: Alfred A. Knopf, 1979.
Web sites:
“Animals of the Florida Scrub: Florida Worm Lizard.” Flori-Data. http://www
.floridata.com/tracks/scrub/animals/rhi_flor.htm (accessed on November
23, 2004).
“Suborder: Amphisbaenia.” Georgia Wildlife Web. http://museum.nhm
.uga.edu/gawildlife/reptiles/squamata/amphisbaenia.html (accessed
on November 23, 2004).
“Wildlife: Florida Worm lizard.” Native Florida. http://www.nsis.org/
gallery/wl-fl_worm_lizard.html (accessed on November 23, 2004).
“Worm lizard.” Fact Monster. http://www.factmonster.com/ce6/
sci/A0852748.html (accessed on November 23, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Amphisbaenia
Family: Trogonophidae
Number of species: 8 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class At first glance, the spade-headed wormlizards look like big
earthworms. Just as earthworms have rings around their bod-
subclass
ies, these wormlizards have thin rings from the back of the head
order to the tip of the tail. Such rings are called annuli (ANN-you-
monotypic order lie). In the spade-headed wormlizards, the rings are made of
tiny square-shaped scales that are the same size and shape from
suborder the belly to the back. Also like earthworms, the wormlizards
▲ family have no legs. Wormlizards, however, do still have tiny leftover
hip and shoulder bones inside their bodies.
The heads of spade-headed wormlizards are shaped like shov-
els, or spades, which gives them their name. Sometimes, people
also call them by another common name, short-headed worm-
lizards, because their heads are quite small and end quickly af-
ter the neck. The edges of the face are quite sharp, providing an
excellent digging tool for these burrowing animals. The body is
flattened into an upside down “U” shape, so that the wormlizard
has a rounded back and an inward-curved belly side. It has a
very short, sometimes ridged, or keeled, tail. The tail begins at
the vent, a slit-like opening on the underside of the animal.
Some spade-headed wormlizards are patterned with checks
and spots. They are rather small animals, with adults ranging
from 3.1 to 9.4 inches (8 to 24 centimeters) in length.
GEOGRAPHIC RANGE
They live in northern Africa, in eastern Somalia, and in
the Middle East from western Iran to the island of Socotra,
HABITAT
Spade-headed wormlizards tunnel in loose
soils, which may be sandy or loamy. A loamy
soil is one that is not quite as grainy as sand LIZARD EARS
but still is quite loose.
On a person, a dog, or a cat, the ears
DIET are obvious. They are called “external” ears
Most of the spade-headed wormlizards eat because external means something that is
termites, grubs, and ants. Grubs are actually on the outside. Some animals, including
young beetles, which are also known as bee- many reptiles, have no external ears.
tle larvae (LAR-vee). When the grubs are old Instead, their ears are often little more than
enough, they go through another life stage holes on the sides of the head. Some
called pupae (PYU-pee) and then turn into species do not even have the holes. They
the adult crawling beetles familiar to most are covered with scales. Spade-headed
people. Wormlizards in captivity will also eat wormlizards are an example of reptiles
larger animals by biting off chunks and without external ear openings. They can,
chewing them up. Scientists are unsure if however, still hear and are especially good
they eat larger animals in the wild because at hearing vibrations in the soil. Such
they have never seen a wild wormlizard eat- vibrations could be made by a predator
ing a larger animal. On the rare occasions walking overhead or a prey animal moving
when they have been able to catch and cut about.
open a wild wormlizard to check its stomach
and see what it had been eating, scientists
have not found pieces of large animals inside. Until more stud-
ies on wormlizards are done, scientists cannot say for sure
whether they eat larger animals in the wild.
CONSERVATION STATUS
These species are not considered endangered or threatened,
but scientists know little about them in the wild.
SPECIES
NO COMMON NAME ACCOUNT
Agamodon anguliceps
Diet: Scientists have not studied this animal in the wild, but they
suspect that it eats termites, grubs, and other invertebrates (in-VER-
teh-brehts), which are animals without backbones. In captivity, how-
ever, this wormlizard can also attack and kill larger vertebrate prey,
which they then eat by biting off and chewing up the pieces. Verte-
brates (VER-teh-brehts) are mammals and other animals that have
backbones.
Books:
Burnie, David, and Don Wilson eds. “Amphisbaenians.” The Definitive Vi-
sual Guide to the World’s Wildlife New York: DK Publishing, 2001.
Web sites:
“Amphisbaenia.” Virtual Museum of Natural History. http://www.curator.
org/LegacyVMNH/WebOfLife/Kingdom/P_Chordata/ClassReptilia/
O_Squamata/InfraAmphisbaenia/amphisbaenia.htm (accessed on No-
vember 15, 2004).
“Family Trogonophidae (Shorthead Worm Lizards).” EMBL Reptile
Database. http://www.embl-heidelberg.de/uetz/families/Trogonophidae
.html (accessed on November 15, 2004).
“The Keeping and Maintenance of Amphisbaenians.” Cyberlizard.
http://www.nafcon.dircon.co.uk/amphisb1.html (accessed on Novem-
ber 15, 2004).
“Order Squamata, Suborder Amphisbaenia (worm-lizards).” San Fran-
cisco State University. http://online.sfsu.edu/uy/AnimDiv/lab/lab8/
Biol171Lab8.html. (accessed November on 15, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Scincomorpha
Family: Xantusiidae
Number of species: 23 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The night lizards are mainly small lizards without the work- class
ing eyelids that many other species of lizards have. Instead, the
night lizards have a see-through scale covering the eye. This subclass
clear scale, which looks somewhat similar to a person’s contact order
lens, is called a spectacle. Beneath the spectacle, the eyes of
some species of night lizards have catlike pupils, but others monotypic order
have round pupils. The typical night lizard has a low flat body, suborder
which allows it to sneak easily into cracks of rocks or into nar-
▲ family
row openings between plant leaves.
The bodies of these lizards are covered with small scales, ex-
cept on the head and belly. The top of the head is covered with
large plates, and wide rectangular scales stretch across the belly.
Most have drab-colored bodies, usually brown or gray, but a few
have striking patterns. The granite night lizard, for example, has
a spotted leopard-style pattern of brown spots on an otherwise
yellowish body. Some have round and bumpy scales that give
the lizard’s back the look of a tiny beaded purse. Some night
lizards are quite small, reaching only 1.5 inches (3.7 centime-
ters) long from the tip of the snout to the vent, a slit-like open-
ing at the beginning of the tail and on the underside of the lizard.
Adults of the largest species, the yellow-spotted night lizard,
grow to more than three times that size, reaching 5 inches (12.7
centimeters) long from the snout to the vent. The typical night
lizard has a tail as long or slightly longer than its body.
GEOGRAPHIC RANGE
Night lizards live in the United States, Cuba, and Mexico, as
well as in Central America as far south as Panama.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), one
species of night lizard is Vulnerable, which means that it faces
a high risk of extinction in the wild. The U.S. Fish and Wildlife
Service lists the same species, the island night lizard, as Threat-
ened, which means that it is likely to become endangered in
the foreseeable future. The island night lizard is at risk because
people have brought pigs and goats to the three small Channel
Islands where the lizard lives. These much larger animals eat
the plants that the lizards use as their homes. Efforts are now
under way to remove pigs and goats from at least one of the
three islands. Although no other species have been named as
being at risk, many night lizards are threatened by habitat de-
struction. When humans cut down rainforests, remove plants,
or otherwise destroy the places where the lizards live, whole
populations of these animals can disappear.
SPECIES
ACCOUNT DESERT NIGHT LIZARD
Xantusia vigilis
Habitat: The desert night lizard also goes by the common name
yucca night lizard, because it spends much of its time in clumps of
Diet: The desert night lizard eats ants and beetles and occasionally
some other insects that it finds in the plants where it lives.
Desert night lizards and people: Although desert night lizards can be
very numerous in some places, with twelve thousand individuals in an
area of just one square mile (or four thousand in a square-kilometer
area), people rarely see this shy lizard. Humans can, however, harm the
lizard populations by cutting down and removing yucca and agave
plants, which often happens when they clear land to make way for
houses.
Books:
Alvarez del Toro, M. Los reptiles de Chiapas. 3rd edition. Chiapas, Mexico:
Instituto de Historia Natural, Tuxtla Gutierrez, 1982.
Web sites:
“Family Xantusiidae (Night Lizards).” Animal Diversity Web. University of
Michigan Museum of Zoology. http://animaldiversity.ummz.umich.edu/
site/accounts/classification/Xantusiidae.html (accessed on November
15, 2004).
“Granite Night Lizard.” Western Ecological Research Center, U.S.
Geological Survey Biological Resources Division. http://www.werc.usgs
.gov/fieldguide/xahe.htm (accessed on November 15, 2004).
“Island Night Lizard.” eNature. http://www.enature.com/fieldguide/
showSpeciesSH.asp?curGroupID=7&shapeID=1059&curPageNum=
50&recnum=AR0662 (accessed on November 16, 2004).
“Night Lizard.” Wikipedia, the free encyclopedia. http://en.wikipedia.org/
wiki/Xantusiidae (accessed on November 15, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Sauria
Family: Lacertidae
Number of species: at least 225
family C H A P T E R species
GEOGRAPHIC RANGE
Wall and rock lizards live in Europe, Asia, Africa, and the
East Indies.
DIET
The bellies of these lizards are usually filled with insects,
which they typically capture by sitting very still in one spot—
usually in the shade—until an insect wanders by. They then
spring out and grab the tasty morsel. This type of hunting is
called ambush. The western sandveld lizard is unusual because
while it eats some insects, its main diet is scorpions, which the
lizard finds by looking for their tunnel entrances and digging
them out of the ground. Some species in this lizard family also
eat seeds and fruit in addition to insects. A few, including the
adult giant lizards that live in the Canary Islands, are unique
in that they eat almost only plant material.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), Si-
mony’s giant lizard is Critically Endangered, which means that
it faces an extremely high risk of extinction in the wild. This
giant lizard is so rare that scientists actually thought it was ex-
tinct until a small population turned up in 1975 high in the
cliffs of El Hierro, one of the Canary Islands. Another species,
called the Gomeran giant lizard, was similarly thought to be
extinct until 2001 when a population was discovered in the Ca-
naries. It may be even more rare than Simony’s giant lizard, but
the IUCN has not yet listed it as being at risk. The greatest
predators to these lizards are cats and rats, which were both
brought to the islands by humans.
In addition to Simony’s giant lizard and the Gomeran giant
lizard, the IUCN has listed Clark’s lacerta as Endangered, which
SPECIES
SAND LIZARD ACCOUNT
Lacerta agilis
Habitat: The sand lizard is common in places with sandy soils, such
as sand dunes and brushy areas, but it can also make its home in clay-
type soils along forest edges and in fields and gardens.
Sand lizards and people: Humans and this lizard rarely see one
another.
Conservation status: Although neither the IUCN nor the U.S. Fish
and Wildlife Service list this species as threatened, some populations
are at great risk because of the destruction of their habitat. In west-
ern Europe, the lizards typically live in heathlands, which are open
areas covered with low plants and shrubs. When the heathlands are
destroyed to make way for homes or other human development, the
lizards disappear. ■
Books:
Behler, John, and F. Wayne King. “Typical Old World Lizard Family
(Lacertidae),” National Audubon Society Field Guide to Reptiles and
Amphibians. New York: Alfred A. Knopf, 1979.
Böhme, W., ed. Handbuch der Reptilien und Amphibien Europas. 2 vols.
Wiesbaden, Germany: AULA Verlag, 1984–1986.
Branch, B. Field Guide to the Snakes and Other Reptiles of Southern
Africa. Capetown, South Africa: Struik Publishers, 1998.
Burnie, David, and Don Wilson, eds. The Definitive Visual Guide to the
World’s Wildlife New York: DK Publishing, 2001.
Halliday, Tim, and Kraig Adler. The Encyclopedia of Reptiles and
Amphibians. New York: Facts on File, 1986.
Mattison, Chris. Lizards of the World. New York: Facts on File, 1989.
Valakos, E.D., W. Böhme, V. Perez-Mellado, and P. Maragou, eds.
Lacertids of the Mediterranean Region: A Biological Approach. Athens,
Greece: Hellenic Zoological Society, 1993.
Web sites:
“Common lizard, viviparous lizard.” BBC. http://www.bbc.co.uk/nature/
wildfacts/factfiles/282.shtml (accessed on November 19, 2004).
“Lacerta agilis—Sand Lizard.” First Nature. http://www.first-nature
.com/reptiles/lacerta_vivipara.htm (accessed on November 19, 2004).
“Lacerta vivipara—Common Lizard.” First Nature. http://www.first-nature
.com/reptiles/lacerta_agilis.htm (accessed on November 19, 2004).
“Sand Lizard.” BBC. http://www.bbc.co.uk/nature/wildfacts/factfiles/
283.shtml (accessed on November 19, 2004).
“Sand Lizard (Lacerta agilis).” ARKive. http://www.arkive.org/species/
ARK/reptiles/Lacerta_agilis/more_moving_images.html (accessed on
November 19, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Lacertiformes
Family: Gymnophthalmidae
Number of species: At least 175
species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The microteiids are very small lizards, with adults usually
only growing to 2.3 inches (6 centimeters) long from the tip
subclass
of the snout to the vent, which is a slitlike opening between
order the two hind legs on the underside of the lizard. Their tails
monotypic order come in different lengths depending on the species, but they
are typically about one and one-half times the length of the
suborder body from snout to vent or longer. All species in this family
▲ family can easily break off the tail and grow a new one. Most, but
not all, have four working legs. The eighteen species in the
group, or genus (GEE-nus), called Bachia have tiny legs, and
those in the genus Calyptommatus have no legs at all. A genus
is a group of similar species. Although the microteiids
spend much of their time hidden in dark places, they have well-
formed eyes.
Many species in this family have small scales on their backs
and larger scales on their undersides. Some species have ridges,
or keels, on their back scales, and some have smooth unkeeled
scales. Many have backs in shades of brown or black, and some
have stripes or spots. In a few species, such as the golden spec-
tacled lizard of Costa Rica, the tail may be a different color than
the rest of the lizard.
GEOGRAPHIC RANGE
Microteiids live in southern Mexico, in Central America, on
the Caribbean islands, and throughout much of South America,
where they reach as far south as north-central Argentina.
Microteiids 229
which are mammals, birds, and other animals with backbones.
Most vertebrates require that a female and male mate before
the female becomes pregnant. In the microteiid lizards, how-
ever, a female can become pregnant without ever seeing a male
and produces babies that are her exact duplicates. Such exact
duplicates are called clones.
CONSERVATION STATUS
These species are not considered endangered or threatened,
but scientists know little about them. Because they live along
the ground, however, and sometimes in very small areas, habi-
tat destruction can wipe out entire populations.
SPECIES
NO COMMON NAME ACCOUNT
Bachia bresslaui
Microteiids 231
Bachia bresslaui live in the
South American countries of
Paraguay and Brazil. (Illustration
by Barbara Duperron.
Reproduced by permission.)
openings on the sides of the head for ears, this species has no such
openings. Of the few individuals that have ever been seen, the largest
of this rare species of lizards reached a size of 4.2 inches (10.6
centimeters) in length from the snout to the vent, plus a tail that mea-
sured more than 6.3 inches (16 centimeters) long.
Diet: Scientists have studied only five individuals from this species.
These five ate ants, scorpions, spiders, beetles, and beetle grubs.
Bachia bresslaui and people: People and this lizard rarely see
one another. Humans do, however, sometimes destroy their habitat
when they build on or otherwise change the areas where the
lizards live.
Books:
Avila-Pires, T. C. S. Lizards of Brazilian Amazonia (Reptilia: Squamata).
Leiden, Germany: Zoologische Verhandelingen, 1995.
Cogger, H. G., and R. G. Zweifel, eds. Encyclopedia of Reptiles and
Amphibians. 2nd ed. San Diego: Academic Press, 1998.
Dixon, J. R., and P. Soini. The Reptiles of the Upper Amazon River Basin,
Iquitos Region, Peru. 2nd rev. ed. Milwaukee: Milwaukee Public Museum,
1986.
Mattison, Chris. Lizards of the World. New York, NY: Facts on File, 1989.
Murphy, J. C. Amphibians and Reptiles of Trinidad and Tobago. Malabar,
FL: Krieger, 1997.
Pianka, E. R., and L. J. Vitt. Lizards: Windows to the Evolution of
Diversity. Berkeley: University of California Press, 2003.
Pough, F. H., R. M. Andrews, J. E. Cadle, M. L. Crump, A. H. Savitzky, and K.
D. Wells. Herpetology. 2nd ed. Upper Saddle River, NJ: Prentice Hall, 2001.
Powell, R., and R. W. Henderson, eds. Contributions to West Indian
Herpetology: A Tribute to Albert Schwartz. Contributions to Herpetology,
Volume 12. Ithaca, NY: Society for the Study of Amphibians and Rep-
tiles, 1996.
Schwartz, A., and R. W. Henderson. Amphibians and Reptiles of the West
Indies: Descriptions, Distributions, and Natural History. Gainesville, FL:
University of Florida Press, 1991.
Vitt, L. J., and S. de la Torre. A Research Guide to the Lizards of Cuyabeno.
Museo de Zoologia (QCAZ) Centro de Biodiversidad y Ambiente Pontificia
Universidad Catolica del Ecuador, 1996.
Zug, G. R., L. J. Vitt, and J. L. Caldwell. Herpetology: An Introductory Bi-
ology of Amphibians and Reptiles. 2nd ed. San Diego: Academic Press,
2001.
Web sites:
“A Brief Look at the Gymnophthalmidae Spectacled Lizards
and Microteiids.” Cyberlizard. http://www.nafcon.dircon.co.uk/
gymnophthalmidae. htm (accessed on November 12, 2004).
“Genus Bachia.” Animal Diversity Web. University of Michigan Museum
of Zoology. http://animaldiversity.ummz.umich.edu/site/accounts/
classification/Bachia.html (accessed on November 15, 2004).
Microteiids 233
“Golden Spectacled Lizard (Gymnophthalmus speciosus),” Savannah
River Ecology Laboratory Herpetology Program. http://www.uga.edu/
srelherp/jd/jdweb/Herps/species/Forlizards/Gymspe.htm (accessed on
November 12, 2004).
“Gymnophthalmidae.” Animal Diversity Web. University of Michigan
Museum of Zoology. http://animaldiversity.ummz.umich.edu/site/
accounts/classification/Gymnophthalmidae.html (accessed on Novem-
ber 15, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Lacertiformes
Family: Teiidae
Number of species: 18 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The whiptail lizards, tegus, and other members of this fam- class
ily have long, thin bodies with long legs and narrow heads with
subclass
noticeable eyes and long, forked tongues. Their tails often
stretch one-and-a-half times as long as the rest of their bodies order
and sometimes more. Some are camouflaged in drab browns, monotypic order
but others are colored in bright greens, reds, and blues. Their
overall size may be small or large, depending on the species. In suborder
some, the adults are less than 5 inches (12 centimeters) long ▲ family
from the tip of the head to the end of the tail, while other species
when full-grown are 4 feet 3 inches (1.3 meters) long from head
to tail. In most cases, the males are a bit bigger than the females.
GEOGRAPHIC RANGE
Species of this family live only in the Western Hemisphere,
from the United States south through Mexico and Central
America to South America. Some species also make their homes
on many islands of the Caribbean.
HABITAT
Whiptail lizards, tegus, and other members of this family tend
to live in places that have some open areas where they can sun-
bathe, or bask. Even those that live in seemingly thick forests
can find many openings in the tree cover and sit where the sun-
shine warms the ground. Usually, the larger species tend to make
their homes in shadier habitats, while their young and the smaller
species live in the sunniest, most open areas. When they aren’t
basking or looking for food, most species stay underground in
CONSERVATION STATUS
According to the World Conservation Union (IUCN), two
species are Extinct, which means they are no longer in exis-
tence. In addition, two are Critically Endangered and face an
extremely high risk of extinction in the wild, and one is Vul-
nerable and faces a high risk of extinction in the wild. The
IUCN also describes two species as Data Deficient, which means
that scientists do not have enough information to make a judg-
ment about the threat of extinction. The U.S. Fish and Wildlife
Service also lists two species as Threatened or likely to become
endangered in the foreseeable future. Many of the at-risk species
naturally have low numbers because they only live on small is-
lands. In this case, habitat destruction and/or collection can
wipe out whole populations and possibly entire species.
SPECIES
ACCOUNTS SIX-LINED RACERUNNER
Cnemidophorus sexlineatus
CROCODILE TEGU
Crocodilurus lacertinus
Diet: They eat almost any insect or spider they can find on land or
in the water.
Books
Badger, D. Lizards: A Natural History of Some Uncommon Creatures—
Extraordinary Chameleons, Iguanas, Geckos, and More. Stillwater, MN:
Voyageur Press, 2002.
Cogger, H. G., and R. G. Zweifel, eds. Reptiles and Amphibians. New
York: Smithmark, 1992.
Web sites
“Great Basin Whiptail.” California Living Museum. http://www.calmzoo
.org/stories/storyReader$81 (accessed on November 5, 2004).
“Lizards of Wisconsin: Special Tricks.” Environmental Education for Kids,
Wisconsin Department of Natural Resources. http://dnr.wi.gov/org/
caer/ce/eek/critter/reptile/lizardsOfWisconsin5.htm (accessed on
November 5, 2004).
McFarlane, B. “Cnemidophorus sexlineatus.” Animal Diversity Web,
University of Michigan Museum of Zoology. http://animaldiversity.ummz
.umich.edu/site/accounts/information/Cnemidophorus_sexlineatus
.html (accessed on November 5, 2004).
“Prairie Racerunner.” Environmental Education for Kids, Wisconsin
Department of Natural Resources. http://www.dnr.state.wi.us/org/
caer/ce/eek/critter/reptile/prairieracerunner.htm (accessed on Novem-
ber 5, 2004).
“Six-Lined Racerunner.” Davidson College Biology Department.
http://www.bio.davidson.edu/Biology/herpcons/Herps_of_NC/lizards/
Cne_sex.html (accessed on November 5, 2004).
“Unisexual Whiptail Lizards.” American Museum of Natural History.
http://www.amnh.org/exhibitions/expeditions/treasure_fossil/Treasures/
Unisexual_Whiptail_Lizards/lizards.html?50 (accessed on November 5,
2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Sauria
Family: Cordylidae
Number of species: 88 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The plated lizards and the girdled lizards, which have often class
been separated into their own individual families, are heavy-
subclass
bodied lizards. The plated lizards have tails that are much longer
than the body and are covered with long, rectangular scales. Gir- order
dled lizards include the flat lizards, girdle-tailed lizards, and the monotypic order
grass and snake lizards. They have shorter tails that are only
about the same length as the rest of the body and are usually suborder
covered with spiny scales. The flat lizards have greatly flattened ▲ family
bodies and have few if any spiny scales. The grass and snake
lizards have tiny, barely usable limbs that look more like little
spines than arms and legs. These lizards slither like snakes.
Many species of plated and girdled lizards are drab-colored
and blend into the background. In others, the females and ju-
veniles are dull, but the adult males are brightly and beauti-
fully colored. The girdle-tailed and flat lizards range from 5 to
13 inches (13 to 33 centimeters) in length from head to tail tip;
adult grass lizards grow to about 22 inches (56 centimeters) in
length, and adult plated lizards reach from 6 to 28 inches (15
to 71 centimeters) in total length.
GEOGRAPHIC RANGE
These lizards live in southern Africa and in Madagascar.
HABITAT
The flat and girdle-tailed lizards, along with many plated
lizards, typically make their homes in rocky, dry areas, although
CONSERVATION STATUS
According to the World Conservation Union (IUCN), one
species of plated lizard is Extinct, which means that it is no
longer in existence. Only two specimens of this lizard, called
the Eastwood’s long-tailed seps, are known. In addition, five
species of plated and girdled lizards are Vulnerable, which
means that they face a high risk of extinction in the wild, and
five species are Near Threatened, which means that they are
likely to qualify for a threatened category in the near future.
Many of them live in tiny areas that are now being developed
for other uses. A number of the lizards are also very beautiful,
which has made them quite desirable for the pet trade.
SPECIES
ACCOUNT CAPE FLAT LIZARD
Platysaurus capensis
the underside of the lizard at the beginning of the tail. The tail dou-
bles the overall size, for a total length of about 5 to 6.6 inches (12.8
to 16.8 centimeters).
Geographic range: The cape flat lizard lives in the far southwest
portion of Africa, in both South Africa and Namibia.
Habitat: They live in those areas of desert that have many rocks.
Behavior and reproduction: Cape flat lizards are shy animals that
run for cover when humans or other potential predators come too
close. People usually see them from a distance on top of rocks, es-
pecially granite ledges. They may live in small groups. Females lay
eggs in November or December and sometimes again a couple of
months later. Each time, she lays two large eggs in moist soil beneath
or in the crack of a rock.
Cape flat lizards and people: Because they live in deserts away from
humans, lizards and humans rarely bother one another.
Books
Badger, D. Lizards: A Natural History of Some Uncommon Creatures—
Extraordinary Chameleons, Iguanas, Geckos, and More. Stillwater. MN:
Voyageur Press, 2002.
Branch, Bill. Field Guide to Snakes and Other Reptiles of Southern Africa.
South Africa: Struik Publishers, 1998.
Glaw, Frank, and Miguel Vences. Field Guide to the Amphibians and
Reptiles of Madagascar. 2nd ed. Privately printed, 1994.
Mattison, Chris. Lizards of the World. New York, NY: Facts on File, 1989.
Web sites
“Cordylids of the Cederberg.” Cape Nature Conservation. http://www
.capenature.org.za/cederbergproject/html/cordylids.html (accessed on
October 18, 2004).
“Cordylus spp.” Melissa Kaplan’s Herp Care Collection. http://www
.anapsid.org/cordylus.html (accessed on October 18, 2004).
“Plated lizards.” Melissa Kaplan’s Herp Care Collection. http://www
.anapsid.org/plated.html (accessed on October 18, 2004).
“Plated lizards of the Cederberg.” Cape Nature Conservation. http://
www.capenature.org.za/cederbergproject/html/platedlizards.html
(accessed on October 18, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Sauria
Family: Scincidae
Number of species: About 1,400
species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
With about 1,400 species, the skinks come in many different class
sizes, shapes, and colors, but they do share a few features. Mem-
subclass
bers of this family have large head scales, body scales that have
bony plates underneath them, and a roof of the mouth that is order
made of two, flat bony plates instead of one, as humans and monotypic order
other animals have. The bony plate is called a palate (PAL-iht).
suborder
The skinks are divided into four major groups or subfamilies.
The seventeen species in two of the subfamilies are legless, while ▲ family
the hundreds of species in the other two subfamilies have legs.
A few species, known as comb-eared skinks, have noticeable
scales that stick out near the ear opening on the side of the head.
Skinks, most of which have smooth scales, may be either
small or large. The smallest adults grow to just 0.9 inches (2.3
centimeters) long from the tip of the head to the vent, which
is a slit-like opening on the belly side of the lizard. If the lizard
has legs, the vent is located between them. The longest skink
is 20 times larger than the smallest, reaching 19.3 inches (49
centimeters) from the snout to the vent.
Color varies among the skinks, but many have rather drab,
brownish bodies. The males of numerous species, however, of-
ten develop colorful heads during the breeding season. In many
species, juveniles have bright blue, red, or yellow tails, which
are believed to help them escape attacks by predators (PREH-
dih-ters), or animals that hunt them for food. The predator
snaps at the colored tail, which the young skink drops before
running away. Adults are also able to lose their tails and survive.
Skinks 249
GEOGRAPHIC RANGE
They live on land almost around the world, except for many
islands in the ocean and very cold places, such as Antarctica
and high up in mountains.
HABITAT
Many skinks live mostly underground, hidden beneath logs,
rocks, or among piles of leaves and twigs. Many of those that
live underground dig their own burrows. The night skink builds
a large tunnel system, which is marked by a large pile of sand
near the most-used entrance. This lizard often has to share its
tunnels with other animals that drop in day and night to sleep
or to escape the weather or a predator. Some other species of
skinks are good climbers and spend time on tree branches and
tree trunks. While most of them live on land, some do not mind
taking a dip in the water. Several species, like Gray’s water skink
and the eastern water skink, spend part of their time in ponds
or streams.
DIET
Most species enjoy insects. Some are rather picky eaters and
prefer to eat one kind of insect. Some of the underground-
living, legless skinks, for example, eat mostly termites. A few
species of skinks, including bobtails and sandfish, mix some
flowers and grains into their insect diets, and others, such as
the prehensile-tailed skink, are strictly vegetarian.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), three
species are Extinct, which means they are no longer in existence.
Twenty-six others are listed as Critically Endangered, Endan-
gered, or Vulnerable, which means they face an extremely high,
Skinks 251
very high, or high risk of extinction in the wild. Five are Near
Threatened and are likely to qualify for a threatened category in
the near future; and seven are Data Deficient, which means sci-
entists need more information before they can make a judgment
about the threat of extinction. The U.S. Fish and Wildlife Serv-
ice lists three skinks as Threatened or likely to become endan-
gered in the foreseeable future: the Round Island, bluetail mole,
and sand skinks.
SPECIES
PREHENSILE-TAILED SKINK ACCOUNTS
Corucia zebrata
Skinks 253
Unlike the vast majority of other
skinks, the prehensile-tailed
skink is a strict vegetarian and
particularly likes leaves and
flowers it finds in the trees.
(Illustration by Barbara Duperron.
Reproduced by permission.)
Diet: Unlike the vast majority of other skinks, this species is a strict
vegetarian and particularly likes leaves and flowers it finds in the trees.
BROAD-HEADED SKINK
Eumeces laticeps
Skinks 255
Female broad-headed skinks lay
six to ten eggs at a time under
leaves or in some other hiding
spot and stay with them until
they hatch. (©Larry L. Miller/
Photo Researchers, Inc.
Reproduced by permission.)
Diet: They spend much of their time looking for insects and other
invertebrates (in-VER-teh-brehts), which are animals without back-
bones, to eat.
SANDFISH
Scincus scincus
Skinks 257
When it feels threatened, the
sandfish dives headfirst into the
sandy ground and swims below
the surface of the sand.
(Illustration by Barbara
Duperron. Reproduced by
permission.)
Sandfish and people: Native people hunt sandfish for their meat.
At one time, people believed that dead dried sandfish could cure var-
ious diseases.
Books
Badger, D. Lizards: A Natural History of Some Uncommon Creatures—
Extraordinary Chameleons, Iguanas, Geckos, and More. Stillwater, MN:
Voyageur Press, 2002.
Greer, Allen E. The Biology and Evolution of Australian Lizards. Chipping
Norton, Australia: Surrey Beatty and Sons, 1989.
Hutchinson, M. N. “Family Scincidae.” In Fauna of Australia. Vol. 2A,
Amphibia and Reptilia, edited by C. J. Gasby, C. J. Ross, and P. L. Beesly.
Canberra: Australian Biological and Environmental Survey, 1993.
Periodicals
“Black Market Animals: The Stealing, Smuggling and Selling of Endan-
gered Species as Pets is a $10 Billion Illegal Business Worldwide.” Cur-
rent Events, a Weekly Reader publication (April 14, 1997): 2A.
Geschickter, Jacqueline. “Say Ahhhh!” National Geographic World
(November 2000): 31.
Thompson, Sharon. “Attention, Lizard Parents!” National Geographic
World (May 2002): 6.
Web sites
“Blue-tongued Skink.” Enchanted Learning. http://www.enchantedlearn
ing. com/subjects/reptiles/lizard/Bluetonguedskink.shtml (accessed on
November 3, 2004).
“Eastern Water Skink.” Australian Museum. http://www.amonline.net
.au/wild_kids/freshwater/water_skink.htm (accessed on November 3,
2004).
“Many-lined Skink.” Yahooligans! Animals. http://yahooligans.yahoo.
com/content/animals/species/4414.html (accessed on November 3,
2004).
Vanwormer, E. 2002. “Eumeces fasciatus (five-lined skink).” Animal
Diversity Web, University of Michigan Museum of Zoology. http://
animaldiversity.ummz.umich.edu/site/accounts/information/Eumeces_
fasciatus.html (accessed on November 03, 2004).
Other sources
McCoy, Mike. Reptiles of the Solomon Islands. CD-ROM. Kuranda,
Australia: ZooGraphics, 2000.
Skinks 259
ALLIGATOR LIZARDS,
GALLIWASPS, AND
RELATIVES
Anguidae
▲
Class: Reptilia
Order: Squamata
Suborder: Sauria
Family: Anguidae
Number of species: 112 species family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class This family contains four groups of lizards: the glass lizards
subclass and slowworms, the legless lizards, the galliwasps, and the al-
ligator lizards. Many of these species in the Anguidae family
order have bodies that are nearly all brown, but some are green, and
monotypic order others have stripes or bands. The glass lizards have especially
suborder shiny scales. In a few species, the males are more brightly col-
ored than the females. Among alligator lizards that live in
▲ family mountainous areas, for example, the females and the juveniles
are a drab brown, and the males are bright green or yellowish
green. Some, such as the La Selle galliwasp, are small and reach
only about 2.8 inches (7 centimeters) in length from head to
tail tip. The slowworm, on the other hand, can grow to nearly
20 times that size at 55.1 inches (140 centimeters) long.
In general, the scales of these species are thick and strong, giv-
ing them an armor-like covering. Many of the legless lizards and
galliwasps have a fold on each side of the body, which allows
their bodies to stretch out when they eat a particularly big meal
or when a female is pregnant. Some of the species, including the
legless lizards, have no limbs and therefore slither about with a
twisting motion. A few, such as the Moroccan glass lizard, have
no front legs but do have tiny hind legs that look like small flaps
located near the vent, which is a slitlike opening on the under-
side of the animal. The tail in galliwasps, legless lizards, and al-
ligator lizards is usually shorter than the rest of the body, but
the tail is far longer than the body in glass lizards. In all lizards,
including those without legs, the tail begins at the vent. A few
GEOGRAPHIC RANGE
These lizards live in North, Central, and South America, Eu-
rope, and Asia. They also make their homes on many islands
of the West Indies. One species, the Moroccan glass lizard, lives
in northern Africa.
HABITAT
Most of these lizards live on land and on the ground’s sur-
face, but they often remain in leaf piles, under stones, or in
some other hiding spot. A few make their homes underground,
and some spend much of their time in trees. While many species
live in moist, low-lying areas, some live high in mountain
forests or in dry and shrubby deserts.
DIET
These lizards will eat a number of different animals. They
typically move very slowly, so their diet includes other slow-
traveling things, such as snails, slugs, spiders, some insects, and
other invertebrates (in-VER-teh-brehts), which are animals with-
out backbones. When they eat vertebrates (VER-teh-brehts),
which are animals with backbones, they tend to dine on bird
eggs, baby rodents that are still in the nest, or other small ani-
mals, such as salamanders, that are not fast enough to get away.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), one
species is Extinct, which means that it is no longer in existence.
This species, the Jamaica giant galliwasp, was last seen in 1840.
It probably disappeared because people brought new species, in-
cluding the mongoose, to Jamaica to kill rats. The mongoose,
SPECIES
ACCOUNT TEXAS ALLIGATOR LIZARD
Gerrhonotus liocephalus
Geographic range: They live from Texas in the United States to San
Luis Potosí in central Mexico.
Books
Badger, D. Lizards: A Natural History of Some Uncommon Creatures—
Extraordinary Chameleons, Iguanas, Geckos, and More. Stillwater, MN:
Voyageur Press, 2002.
Capula, Massimo. Simon and Schuster’s Guide to Reptiles and
Amphibians of the World. New York: Simon and Schuster, 1989.
Grismer, L. Lee. Amphibians and Reptiles of Baja California, Including Its
Pacific Islands and the Islands in the Sea of Cortés. Berkeley: University
of California Press, 2002.
Mattison, Chris. Lizards of the World. New York, NY: Facts on File, 1989.
Web sites
“Alligator Lizard.” Melissa Kaplan’s Herp Care Collection.
http://www.anapsid.org/gerrhont.html (accessed on October 20, 2004).
“Eastern Glass Lizard.” Yahooligans! Animals. http://yahooligans
.yahoo.com/ content/animals/species/4313.html (accessed on October
20, 2004).
“Glass Lizard - Glass Snake - Legless Lizard.” Melissa Kaplan’s Herp Care
Collection. http://www.anapsid.org/legless.html (accessed on October
20, 2004).
“Northern Alligator Lizard.” Yahooligans! Animals. http://yahooligans
.yahoo.com/content/animals/species/4322.html (accessed on October
20, 2004).
“Slender Glass Lizard.” Iowa Herpetology. http://www.herpnet.net/
Iowa-Herpetology/reptiles/lizards/glass_lizard.html(accessed on October
20, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Lacertilia
Family: Xenosauridae
Number of species: 6 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
With their flat heads and bodies and lumpy scales, the knob- class
scaled lizards have an unusual look. The head is usually trian-
gular in shape, coming to a point at the tip of the snout. Some subclass
have a very noticeable ridge above the eye and extending for- order
ward to the snout and backward to the rear of the head. Often,
the females have larger bodies than the males, but the males monotypic order
typically have bigger heads. Their bodies are usually dark brown suborder
to black, often with lighter-colored bands or blotches. The
▲ family
largest specimens grow to 4.7 to 5.1 inches (12 to 13 cen-
timeters) long from the tip of the snout to the vent, a slitlike
opening on the belly side of the animal at the beginning of the
tail. The tail stretches nearly as long as the body.
Until 1999, this family only had four species. Discoveries of
two new species—one in 2000 and one in 2002—increased the
number to six. The two new species are known only by their
scientific names: Xenosaurus penai and Xenosaurus phalaroan-
theron. Scientists believe additional species are yet to be iden-
tified. In particular, they suspect that a closer look at some of
the already known knob-scaled lizards may reveal that they
should actually be separated into two or more similar-looking
species. This type of splitting is especially common in animals
that live in small groups that are separated from one another,
so the individuals from one group, or population, never see in-
dividuals from another population.
GEOGRAPHIC RANGE
Knob-scaled lizards live in typically small populations widely
scattered from the Tamaulipas in northeastern Mexico on the
HABITAT
Most knob-scaled lizards live in the mountains. Some species
make their homes in cool cloud forests, while others prefer drier
climates and live in hot, shrubby areas. In both cases, the knob-
scaled lizards take advantage of their flattened shape and seek
out cracks and holes in rocks and bark and other hiding places,
where they spend much of their lives.
At one time, scientists included the Chinese crocodile lizard
in this family. This lizard is now in its own family. Unlike the
knob-scaled lizards, the Chinese crocodile lizard lives most of
its life in or near shallow forest ponds, where it eats tadpoles
and fishes.
DIET
These lizards are ambush hunters, which means that they sit
very still and wait for their meal to come to them. Their meals
are usually made up of insects that happen to come too close
to their hiding places, which are usually in rock crevices. The
lizards quickly grab the insects and gulp them down. Like other
lizards, these species flick their tongues to pick up chemical
odors from their insect prey. They cannot smell with their
tongues, but they can smell with a special organ, called a Ja-
cobson’s organ, that sits above a small opening on the roof of
the mouth. The lizard picks up the chemicals with its tongue
and places them on the opening. A study of tongue-flicking be-
havior in Xenosaurus platyceps found that the young ones
flicked their tongues to smell prey whether the lizards were in
their hiding places or not, while the adult lizards did most of
their tongue-flicking only when they were in holes or cracks.
In other words, the adults were much more interested in find-
ing prey when they were out of sight than when they were in
the open.
At least one species of knob-scaled lizards, the Newman’s
knob-scaled lizard, will also eat bits of plants and some mam-
mal meat. This suggests that the lizards may prefer insects but
will eat just about anything they can find. Scientists call such
animals opportunistic (ah-por-toon-ISS-tik), because they in-
clude almost any kind of plant or animal in their diet—if they
are hungry and the opportunity presents itself.
CONSERVATION STATUS
Although scientists still know little about these species or
their overall population sizes, they are not considered endan-
gered or threatened.
SPECIES
KNOB-SCALED LIZARD ACCOUNT
Xenosaurus grandis
Physical characteristics: With a flat head and body and tall, bumpy
scales, the knob-scaled lizard looks much like the other lizards in this
family. This species, however, has bright red eyes and usually a dark-
brown body, often with tan to cream bands or blotches. It grows to
about 10 inches (25 centimeters) long from the tip of its snout to the
end of its tail. The tail is a bit shorter than the rest of the body. Males
and females are about the same size.
The knob-tailed lizard has bright Conservation status: Although much about this species is unknown,
red eyes and a usually dark- it is not considered endangered or threatened. ■
brown body, often with tan to
cream bands or blotches.
(Illustration by Brian Cressman. FOR MORE INFORMATION
Reproduced by permission.)
Books:
Halliday, Tim, and Kraig Adler, eds. The Encyclopedia of Reptiles and
Amphibians. New York, NY: Facts on File, 1986.
Mattison, Chris. Lizards of the World. New York, NY: Facts on File, 1989.
Web sites:
“Chinese Crocodile Lizard.” Center for Research on Concepts and
Cognition, Indiana University. http://www.cogsci.indiana.edu/farg/harry/
bio/zoo/shinisau.htm (accessed on December 8, 2004).
“Xenosauridae.” Animal Diversity Web. http://animaldiversity. ummz.umich
.edu/site/accounts/information/Xenosauridae.html (accessed on Novem-
ber 16, 2004).
“Xenosauridae.” Virtual Museum of Natural History. http://www.curator
.org/LegacyVMNH/WebOfLife/Kingdom/P_Chordata/ClassReptilia/
O_Squamata/InfraAnguimorphan/SupFDiploglossa/FXenosauridae/
xenosauridae.htm (accessed on December 8, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Scleroglossa
Family: Helodermatidae
Number of species: 2 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The two species in this family, the Gila monster and the Mex- class
ican beaded lizard, are both large, heavy-bodied lizards coated subclass
with small, rounded bumps that look like the beadwork on
clothing. The bumps, which are actually pebblelike scales, cover order
the tops of the arms, legs, head, and tail, as well as the back monotypic order
and sides of the body. These lizards have rather short, but
suborder
strong arms and legs and long, thin claws. The tail may be thin
or thick, depending on how well-fed the individual is. This is ▲ family
because these lizards store fat in their tails. Beaded lizards have
slightly longer tails than the Gila monsters. An average beaded
tail is at least two-thirds the length of the entire body, but the
typical Gila tail is about half the total body length. Unlike many
other lizards, these two species also have thick, forked tongues.
Members of the same species can look very different from one
another. Some adults are brightly patterned, while others are
faded and dull. The patterns may be made up of spots, blotches,
circles, bands, or squiggles on a background of pink, orange,
yellow, dark gray, or black. Juveniles are usually banded.
Gila monsters and Mexican beaded lizards are the only two
venomous (VEH-nuh-mus) lizards in the world. Unlike ven-
omous snakes that deliver venom from the upper jaw and
through grooves in just the two fangs, these lizards store their
venom in the lower jaw and deliver it through grooves in nu-
merous teeth.
Adult Gila monsters and beaded lizards range from 12 to 18
inches (30 to 45 centimeters) from the snout to the vent, which
DIET
Gila monsters and beaded lizards wander through their habi-
tat looking for young rabbits or rodents or snakes and lizard eggs
to eat. They will even climb trees and cacti in search of bird eggs.
CONSERVATION STATUS
The World Conservation Union (IUCN) considers both
species in this family as Vulnerable, which means that they face
a high risk of extinction in the wild. The destruction of their
habitat, particularly as it is developed for housing or other hu-
man uses, is one of the biggest reasons they are at risk. Another
reason for their low numbers is that humans sometimes ille-
gally collect them for the pet trade or for personal pets.
SPECIES
ACCOUNT GILA MONSTER
Heloderma suspectum
Geographic range: The Gila monster makes its home in the south-
western United States and in Sonora, Mexico.
Diet: Gila monsters need to eat only three large meals a year to sur-
vive. They store fat in the tail and then use it up between meals, which
can be several months apart. Their favorite foods include lizard, snake,
and bird eggs, as well as young cottontail rabbits and rodents.
Gila monsters and people: A Gila monster bite can be painful, but
it is almost never fatal to humans. The last reported death from a bite
occurred in 1930. Bites rarely happen, however, and usually result
from a person’s carelessness in picking up the lizard.
Books
Badger, D. Lizards: A Natural History of Some Uncommon Creatures—
Extraordinary Chameleons, Iguanas, Geckos, and More. Stillwater, MN:
Voyageur Press, 2002.
Brown, David E., and Neil B. Carmony. Gila Monster: Facts and Folklore
of America’s Aztec Lizard. Salt Lake City, UT: University of Utah Press,
1999.
Campbell, Jonathan A., and William W. Lamar. The Venomous Reptiles
of Latin America. Ithaca, NY: Comstock Publishing Associates, 1989.
Lowe, Charles H., Cecil R. Schwalbe, and Terry B. Johnson. The Venomous
Reptiles of Arizona. Phoenix: Arizona Game and Fish Department, 1986.
Martin, James, and Joe McDonald. Poisonous Lizards: Gila Monsters and
Mexican Beaded Lizards. Minneapolis, MN: Capstone Press, 1999.
Mattison, Chris. Lizards of the World. New York, NY: Facts on File, 1989.
Web sites
“Gila Monster.” Animal Planet: Corwin’s Carnival of Creatures. http://
animal.discovery.com/fansites/jeffcorwin/carnival/lizard/gilamonster
.html (accessed on October 16, 2004).
“Gila Monster.” Enchanted Learning. http://www.enchantedlearning
.com/subjects/reptiles/lizard/Gilamonster.shtml (accessed on October
16, 2004).
“Gila Monster.” WhoZoo. http://www.whozoo.org/anlife2000/jamiebritt/
gilaindexrev.html (accessed on November 3, 2004).
“Mexican Beaded Lizard.” Lincoln Park Zoo. http://www.lpzoo.com/tour/
factsheets/herps/beaded_lizard.html (accessed on October 16, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Varanoidei
Family: Varanidae
Number of species: About 61
family C H A P T E R species
GEOGRAPHIC RANGE
Australia is home to about one-half of the known species.
Members of this family also live in Africa; central to southern
mainland Asia; Southeast Asia, especially the Malaysian and
Indonesian islands; and Papua, New Guinea.
DIET
Most members of this family are meat-eaters. The smaller
species typically dine on insects, centipedes, worms, and other
invertebrates (pronounced in-VER-teh-brehts), which are ani-
mals without backbones. Medium-sized species eat lizards,
lizard and turtle eggs, and young mammals and birds, while
the very large monitors will capture, kill, and eat deer, mon-
keys, adult birds, wild pigs, buffalo, and other big animals.
Monitors also eat carrion (KARE-ree-un), which is the flesh of
an already-dead animal. They are not picky eaters, and many
will even eat young of their own species. A few species eat fruit.
Members of this family spend a good part of the day look-
ing for food, with some traveling 0.6 mile (1 kilometer) or more
between sunup and sunset. They flick their tongues to pick up
the scent of a prey animal and then rely on their eyesight and
their ears to help hunt down the animal when they get close.
Some species, including the sand monitor, swing their heads
back and forth while flicking their tongues so they can pick up
scents from a wider area and then track animals, especially small
lizards, to their underground burrows. They use their long
claws to dig up the lizards. Other species, such as the Komodo
dragon, sometimes hunt by ambush, which means that they sit
very still so they are not obvious and wait for a prey animal to
wander by. The Komodo dragon then rushes from its hiding
spot and grabs the animal.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), two
species are Vulnerable, which means they face a high risk of
extinction in the wild. These are the Indonesian Komodo
dragon and the Philippine Gray’s monitor. Their low numbers
SPECIES
KOMODO DRAGON ACCOUNTS
Varanus komodoensis
Habitat: Komodo dragons can live in dry or moist habitats and are
good enough swimmers to spend some time in the water.
Diet: They are meat eaters, dining on deer, pigs, other mammals,
lizards, and birds. The juvenile diet includes insects, bird and turtle
eggs, and carrion.
CROCODILE MONITOR
Varanus salvadorii
Diet: They probably eat birds in the wild, but in captivity, they also
eat mice and rats.
Books
Auffenberg, W. The Behavioral Ecology of the Komodo Monitor.
Gainesville: University Press of Florida, 1981.
— The Bengal Monitor. Gainesville: University Press of Florida, 1994.
— Gray’s Monitor Lizard. Gainesville: University Press of Florida, 1988.
Badger, D. Lizards: A Natural History of Some Uncommon Creatures—
Extraordinary Chameleons, Iguanas, Geckos, and More. Stillwater, MN:
Voyageur Press, 2002.
Bennett, D. Monitor Lizards. Natural History, Biology and Husbandry.
Frankfurt am Main: Edition Chimaira, 1998.
Periodicals
Mealy, Nora Steiner. “Creatures from Komodo.” Ranger Rick (August
2001): http://www.findarticles.com/p/articles/mi_m0EPG/is_8_35/
ai_76289139 (accessed on October 18, 2004).
Web sites
“Crocodile Monitor.” Honolulu Zoo. http://www.honoluluzoo.org/Crocodile_
Monitor.htm (accessed on October 18, 2004).
“Komodo Dragon.” Enchanted Learning. http://www.enchantedlearning
.com/subjects/reptiles/lizard/Komodoprintout.shtml (accessed on Octo-
ber 18, 2004).
“Komodo Dragon.” Honolulu Zoo. http://www.honoluluzoo.org/komodo_
dragon.htm (accessed on October 18, 2004).
“Komodo Dragon, Varanus komodoensis, 1998.” San Diego Zoo. http://
library.sandiegozoo.org/Fact%20Sheets/komodo_dragon/Komodo.htm
(accessed on October 18, 2004).
“New Guinea Crocodile Monitor.” Central Florida Zoo. http://www
.centralfloridazoo.org/animals/New_guinea_crocodile_monitor.htm
(accessed on October 18, 2004).
“Varanus komodoensis.” Animal Diversity Web. http://animaldiversity
.ummz.umich.edu/site/accounts/information/Varanus_komodoensis
.html (accessed on October 18, 2004).
“Varanidae.” Animal Diversity Web. http://animaldiversity.ummz.umich
.edu/site/accounts/information/Varanida.html (accessed on October
18, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Anomalepididae
Number of species: 16 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Early blind snakes are small, thin snakes, with many species
reaching just 6 to 10 inches (15 to 25 centimeters) in length
subclass
and less than one-tenth of an ounce (2.8 grams) in weight when
order full-grown. Five of the sixteen species are a bit larger and can
monotypic order top 12 inches (31 centimeters) in length, with some reaching
as much as 16 inches (41 centimeters). The larger species in-
suborder clude the greater blind snake and the four lesser blind snakes
▲ family known by their scientific names. Most members of this family
Anomalepididae have no common names and are known only
by their scientific names. The typical early blind snake has a
dark brown or black body with white, yellow, or pink on the
head and tail. A few species lack the lighter color on the head
and tail and are all reddish brown to brown.
The snakes in this family all have short heads with rounded
snouts, and most have slightly larger scales on the snout than on
the rest of the body. Compared to other snakes, their tongues are
quite short. They have stumpy tails that make up just 1 to 3.4
percent of the snake’s total body length. In snakes, the tail be-
gins at the vent, a slitlike opening on the belly side of the ani-
mal. The tail in half of the early blind snake species is tipped with
a thin, sharp spine. The other species have tails without spines.
They look much like slender blind snakes of the family Lep-
totyphlopidae and blind snakes of the family Typhlopidae. The
snakes in all three families have tube-shaped bodies that are
covered in smooth, round scales. Unlike most snakes that have
belly scales, or ventrals, that are noticeably larger than the scales
GEOGRAPHIC RANGE
Early blind snakes live in southern Central America, across
northern South America and possibly on Trinidad, and then
down the eastern side of South America to northeastern Ar-
gentina. Of the four main groups, or genera (jen-AIR-uh), in
this family, two live from Costa Rica to northern South Amer-
ica. These include the four species in the genus (JEAN-us) (the
singular of genera) Anomalepis and the three species in the
genus Helminthophis. The two species of the genus Typhlophis
live only in South America, from central Venezuela eastward
through French Guiana and southward through northeastern
Brazil. One species may extend onto Trinidad. The largest genus
is Liotyphlops with eight species. Some of these live from Costa
Rica into northern South America, and others make their homes
HABITAT
These snakes live most of their lives below the ground; one in-
dividual was reported buried 1.6 feet (0.5 meters) deep in the
soil. They also spend time beneath rocks, logs, and piles of leaves.
Like other underground-living, or fossorial (faw-SOR-ee-ul),
species that stay out of human sight and live in remote areas, sci-
entists know little about them. People have reported these snakes
in a number of different habitats from dry forests to rainforests,
and from low-lying grasslands to nearly 6,000 feet (1,830 meters)
up rocky mountainsides. Although no one has seen early blind
snakes doing it, scientists suspect that they can and do climb trees.
DIET
At least two species eat ant eggs, as well as ant larvae (LAR-
vee) and pupae (PEW-pee), which are the life stages between
the egg and the adult ant. Scientists suspect that other early
blind snakes also eat ants and possibly other insects, but they
have not studied them in enough detail to say for sure.
SPECIES
ACCOUNT LESSER BLIND SNAKE
Liotyphlops ternetzii
Web sites
“Blind snake (Typhlopidae).” MavicaNET. http://www.mavicanet.ru/
directory/eng/24710.html (accessed on October 5, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Leptotyphlopidae
family C H A P T E R Number of species: 93 species
CONSERVATION STATUS
These snakes are not listed as endangered or threatened.
SPECIES
TEXAS BLIND SNAKE ACCOUNT
Leptotyphlops dulcis
Texas blind snakes and people: Texas blind snakes and people
rarely encounter one another.
Books
Brazaitis, P., and M. Watanabe. Snakes of the World. New York: Crescent
Books, 1992.
Burnie, David, and Don Wilson, eds. The Definitive Visual Guide to the
World’s Wildlife. New York: DK Publishing, 2001.
Grace, Eric, ed. Snakes. San Francisco: Sierra Club Books for Children,
1994.
Web sites
“Family Leptotyphlopidae (slender blind snakes and thread snakes).”
Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/
accounts/information/Leptotyphlopidae.html (accessed on September
29, 2004).
“Other Interesting Aspects of Ant Biology.” Rice University. http://
www.ruf.rice.edu/bws/blindsnake.html (accessed on October 7, 2004).
“Photographs of Blindsnakes.” Comparative Physiology and Biome-
chanics Lab at the University of Massachusetts Amherst. http://
marlin.bio.umass.edu/biology/brainerd/kleyphotos.html (accessed on
October 7, 2004).
“Texas Blind Snake.” National Wildlife Federation. http://www.enature
.com/fieldguide/showSpeciesSH.asp?curGroupID=7&shapeID=1060&
curPageNum=1&recnum=AR0724 (accessed on October 7, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Typhlopidae
Number of species: 214 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Most blind snakes are small, with many species reaching less
than 12 inches (31 centimeters) in length at full size. Adult flow-
subclass
erpot snakes, for example, reach only 4 to 6.5 inches (10 to 16.5
order centimeters) long. A few species, however, can grow to more
monotypic order than 24 inches (61 centimeters). The largest, known as Peter’s
giant blind snake or the Zambezi blind snake, can top 3 feet
suborder (0.9 meters) in length and weigh 1.1 pounds (0.5 kilograms).
▲ family The typical blind snake is smooth and shiny with a tube-
shaped body. Usually, the head, body, and tail have about the
same diameter, although in a few of the larger species, the back
half of the animal may grow fat and become quite thick. The
scales on their backs are thick and noticeably overlap one an-
other. In some other families of snakes, the scales barely over-
lap, if they overlap at all. Such an arrangement of overlapping,
thick scales gives the blind snakes a strong protective cover.
Blind snakes have short heads, typically with small eyes cov-
ered by a see-through scale and a small mouth that opens on the
underside of the snake rather than on the front of the head like
most other snakes. In some species, the snout is rounded, but in
others it may flatten out toward the front, become pointed or
hooked, or have some other shape. A few species have little bits
of flesh that stick out of the front of the snout and are used by
the snake to feel its way along the dark, underground tunnels in
which it lives. The tails are usually rather short and often tipped
with a single, thorny spine. The spine is especially noticeable in
Typhlops depressiceps and Acutotyphlops subocularis. The tail in a
HABITAT
Blind snakes are burrowing species that spend most of their
lives either underground or out of sight under logs, tree bark,
stones, or in some other hiding place. Some will even slither
into ant or termite hills. Rainy weather seems to persuade many
blind snakes to leave their underground homes and crawl out
onto land. A few species have been found in trees, but they may
not actually live there and instead be just visiting to look for a
meal. Some blind snakes live in wet rainforests, but other
species survive quite well in deserts. Many others live in grass-
lands, dry forests, farm fields, sandy beaches at the oceanside,
or high up mountainsides. Almost half of the species are found
only on islands, and about 85 percent of all species of blind
snakes live only in the Old World, which includes Asia, Eu-
rope, and Africa in the Eastern Hemisphere.
DIET
Blind snakes eat termites, ants, worms, and other small
invertebrates (in-VER-teh-brehts). Invertebrates are animals
CONSERVATION STATUS
The World Conservation Union (IUCN) lists the Mona Is-
land blind snake as Endangered, which means it faces a very
high risk of extinction in the wild. It also lists the Christmas
Island blind snake as Vulnerable, which means it faces a high
risk of extinction in the wild. Scientists know little about the
wild populations of many species, however, so others may be
at risk.
SPECIES
ACCOUNT BLACKISH BLIND SNAKE
Ramphotyphlops nigrescens
Habitat: People usually see these snakes while turning over rocks
or other items in gardens, farm fields, or even in city lots. The snakes
also live in similar hiding spots in the woods and along the coastline.
Books
Burnie, David, and Don Wilson, eds. The Definitive Visual Guide to the
World’s Wildlife. New York: DK Publishing, 2001.
Cogger, H. G. Reptiles and Amphibians of Australia. Fifth ed. Ithaca, NY:
Comstock Publishing Associates/Cornell University Press, 1994.
Ehmann, H., and M. J. Bamford. “Family Typhlopidae.” In Fauna of
Australia. Vol. 2A, Amphibia & Reptilia, edited by C. J. Glasby, G. J. B.
Ross, and P. L. Beesley. Canberra: Australian Government Publishing
Service, 1993.
FitzSimons, V. F. M. Snakes of Southern Africa. Cape Town and
Johannesburg: Purnell and Sons, 1962.
Grace, Eric, ed. Snakes. San Francisco: Sierra Club Books for Children,
1994.
Greer, A. E. The Biology and Evolution of Australian Snakes. Chipping
Norton, New South Wales, Australia: Surrey Beatty & Sons, 1997.
Web sites
“Blindsnake.” Wild Kids. http://www.amonline.net.au/wild_kids/reptiles/
blind_snake.htm (accessed on September 22, 2004).
“Blind Snakes, Family Typhlopidae.” Australian Museum. http://www
.livingharbour.net/reptiles/snakes_blind.htm (accessed on September
22, 2004).
“Blind Snakes (Family Typhlopidae: South-east Queensland.” Queensland
Museum Explorer. http://www.qmuseum.qld.gov.au/features/snakes/
seq/typhlopidae.asp (accessed on September 23, 2004).
“Brahminy Blind Snake.” Ohio Public Library Information Network.
http://www.oplin.org/snake/fact%20pages/brahminy_blind/brahminy
.html (accessed on September 22, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Anomochilidae
Number of species: 2 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
False blind snakes are also known as dwarf pipe snakes be- class
cause, at first glance, they look very much like small pipe subclass
snakes. Pipe snakes actually fall under a separate family, the
Cylindrophiidae. The false blind snake has a short head and a order
short tail on either end of a tube-shaped body. In snakes, the monotypic order
tail is the portion of the body that begins at the vent, a cross-
suborder
wise opening on the belly side and toward the rear of a snake.
On either side of the vent, these snakes have a tiny bit of bone ▲ family
that sticks out. These bones are called spurs and are seen in a
few other snake families, including the boas.
Their backs are a dark reddish color blotched with yellow-
ish white markings. The eyes and mouth in a false blind snake
are small. In most snakes, the mouth opens at the very tip of
the head, but in false blind snakes, it opens slightly before the
end of the head. Both species in this family have seventeen to
nineteen scale rows. In other words, if a person counted the
number of scales in a straight line from the belly over the back
the snake and back down to the belly, he or she would find
seventeen to nineteen rows. The number of scales on the un-
derside of the snake from front to back is between 222 and 252
in the false blind snake known as Anomochilus leonardi and be-
tween 236 and 248 in the snake Anomochilus weberi. The com-
mon name for both species is false blind snake. The short tail
in both species only has six to eight scales on the underside.
Based on the specimens in museums, adult false blind snakes
range from 8 to 14 inches (20 to 36 centimeters) in length.
GEOGRAPHIC RANGE
False blind snakes are found in Borneo,
the Malaysian Peninsula, and Sumatra.
MYSTERIES BELOW
As humans build ships to travel to space HABITAT
or deep in the oceans, a wide variety of life False blind snakes probably live in loose
forms go unnoticed beneath our feet. Many soil or under leaves, but this is uncertain. Only
of the species that spend their lives out of a few individuals have been found, and these
view in underground tunnels or even just have been spread out in such a way that some
underneath piles of leaves are overlooked. scientists now think that the two species are
The false blind snakes are a good example. really just different populations of one species,
Although they live over a large region in while others believe that the snakes should be
Indonesia, scientists have only found a few split into more than two species.
and have never studied a living specimen.
The same holds true for many other DIET
underground species, which leaves wide False blind snakes probably eat worms and
open a huge area of study for future insect larvae (LAR-vee), which may include
biologists. grubs or caterpillars, but this is just a guess.
No one has studied a live false blind snake.
In addition, no researcher has found a dead
one and opened up its stomach to see what it had been eating.
CONSERVATION STATUS
The World Conservation Union (IUCN) considers the two
false blind snakes to be Data Deficient, which means that sci-
entists as yet have too little information to make a judgment
about the threat of extinction.
SPECIES
ACCOUNT FALSE BLIND SNAKE
Anomochilus leonardi
Habitat: They probably live in loose soil or under leaves, but this
is uncertain.
Web sites
“Family Anomochilidae (Dwarf Pipe Snakes).” Animal Diversity Web.
http://animaldiversity.ummz.umich.edu/site/accounts/information/
Anomochilidae.html (accessed on September 21, 2004).
“Pipe Snakes and Shield Snakes.” Singapore Zoological Gardens.
http://www.szgdocent.org/cc/c-pipe.htm (accessed on September 22,
2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Uropeltidae
Number of species: 47 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Almost all of the forty-seven species of shieldtail snakes have
a head that gets narrower and narrower until it comes to a point
subclass
at the end. In some species, the head gets narrower from side
order to side, and in others it narrows from top to bottom. The pointed
monotypic order snout is covered with thick scales made of fingernail-like mate-
rial, and in some snakes, a particularly large scale makes a roof
suborder over the top of the snout. Many species have a large scale at the
▲ family very end of the tail. This large scale looks something like a shield,
which is how the snakes got their common name of shieldtails.
The large tail scale may have ridges, or keels, or it may be cov-
ered with spines. Often, the snake has other thick and keeled
scales that form a flattened oval just in front of the shield scale.
If the snakes live in wet areas, these keels and spines can pick
up and hold mud, which may form into a large clump.
Many species are brown, gray, or black. Some have dark
bands. A number of species have white or yellowish white out-
lines around their belly scales, which can make them look
rather speckled. Some shieldtails have bright yellow bellies
marked with dark spots, and blue, so-called iridescent (IH-rih-
DEH-sent) backs that shimmer different colors when the light
strikes them. A few species in Sri Lanka look like members of
the cobra family. This type of copying, called mimicry (pro-
nounced MIM-ick-ree), actually causes some birds that might
otherwise attack the snakes to stay away.
Although it cannot be seen from the outside, shieldtail snakes
are different from other snakes in the kind of muscle tissue that
HABITAT
Shieldtail snakes make their homes in forests that may be in
low areas or on the sides of mountains, usually preferring places
with moist or wet ground. They also live in gardens and farm
fields, including rubber plantations. Unlike most digging snakes
that only push through loose soil, the shieldtails will also tun-
nel through quite hard, clay soils. In addition, they will scoot
under leaves or logs.
DIET
Shieldtails mainly eat worms, but some species will also eat
caterpillars and termites, and at least one species in captivity
will eat earwigs. Earwigs are small insects with a pair of pin-
cers on the end of the body. After studying how several species
eat worms, scientists found that the snakes either grab the
worm at the end or in the middle and quickly drag them back
into the burrow. The bodies of those worms caught in the mid-
dle fold in half as they are dragged into the snake’s narrow
burrow.
CONSERVATION STATUS
These species are not listed as endangered or threatened, but
scientists know little about the size of the snakes’ populations.
SPECIES
NILGIRI BURROWING SNAKE ACCOUNT
Plectrurus perrotetii
Geographic range: The snake lives in Nilgiri and the Anamalai Hills
in southern India.
Books
Burnie, David, and Don Wilson, eds. The Definitive Visual Guide to the
World’s Wildlife. New York: DK Publishing, 2001.
Deraniyagala, P. E. P. A Colored Atlas of Some Vertebrates from Ceylon.
Vol. 3, Serpentoid Reptilia. Colombo, Sri Lanka: Government Press,
1955.
Frank, N., and E. Ramus. A Complete Guide to Scientific and Common
Names of Reptiles and Amphibians of the World. Pottsville, PA: NG
Publishing, 1996.
Grace, Eric, ed. Snakes. San Francisco: Sierra Club Books for Children,
1994.
McDiarmid, R. W., J. A. Campbell, and T. A. Toure. Snake Species of the
World, Vol. 1. Washington, DC: The Herpetologists’ League, 1999.
Mehrtens, John M. Living Snakes of the World in Color. New York: Sterling
Publishing, 1987.
Web sites
“Family Uropeltidae (shield-tailed snakes and short-tail snakes).” Animal
Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/
pictures/Uropeltidae. html (accessed on September 22, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Cylindrophiidae
Number of species: 9 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The family name Cylindrophiidae points out one of the pipe
snakes’ most noticeable features: their tube- or cylinder-shaped
subclass
bodies. The family includes nine species, which are often called
order Asian pipe snakes to set them apart from other families of snakes
monotypic order that some people also call pipe snakes. These include the some-
what similar-looking false coral snakes of the family Aniliidae
suborder and the false blind snakes of the family Anomochilidae.
▲ family The pipe snakes are usually dark brown to black with yellow
or reddish bands running from the belly up the sides of the back.
The back bands are sometimes very pale and difficult to see. The
underside of the tail, however, usually has a very bright red or
yellow tip. Some pipe snakes have stripes, and others have light-
colored spots that color the middle of the snake’s back from head
to tail. Counted from one side over the back and down the other
side, they have seventeen to twenty-three rows of scales. The
head, which is no wider than the neck, is rounded and contains
two small eyes with round or slightly oblong pupils and two nos-
trils that each sit inside a single scale. Pipe snakes also have a
very short, pointy tail that is about as thick as the rest of the
body. The tail in a snake begins at the vent, a slitlike opening
on the underside of the animal. Pipe snakes are small- to medium-
sized snakes, ranging from 1 to 3 feet (0.4 to 1 meters) long.
GEOGRAPHIC RANGE
Pipe snakes live in Indonesia, including Borneo, Sumatra,
and Aru Island west of New Guinea; Sri Lanka or Ceylon off
HABITAT
Pipe snakes tend to live in low-lying THE NAME GAME
forests near a water source and in rice pad- Scientific names for animals, such as
dies, but they may also crawl into nearby vil- Cylindrophis ruffus, may appear to be long
lages and towns. They often slither under and confusing, but they actually make it
leaves or into soft, moist soil on the ground. much easier for researchers to tell animals
They are also excellent swimmers. apart. This is because all scientists around
the world use the same scientific names no
DIET matter what language they speak. This is not
The red-tailed pipe snake, and probably the true of common names. For example,
other eight species, eats long and thin animals, among just the English-speaking people,
including other snakes, eels, and lengthy some use the common name of pipe snake
lizards. For this reason, their jaws do not need for the nine species in the family
to open as wide and their necks and bodies Cylindrophiidae, but others use it to mean
do not need to stretch as much as other the species in the family Aniliidae or those
snakes, which eat prey that are larger around. in the family Anomochilidae. A scientific
The pipe snakes are constrictors (kun-STRIK- name has two parts: the genus name, which
tuhrs), which means that the snake will grasp notes the general group to which the animal
its prey by looping its body around the ani- belongs, and the species name, which
mal and squeezing. For small prey, the snake reveals the exact type of animal. In addition,
may hold the animal just until it can reach its the genus name tells scientists which
head around and eat it. For larger animals, the animals are the most closely related. All nine
snake squeezes the prey until it cannot breathe members of the Cylindrophiidae family, for
and stops moving before eating it. People who instance, are of the same genus and are
keep pipe snakes in captivity find that the therefore closely related.
snakes will also eat small mice and fish.
Pipe snakes swallow in an unusual way. Af-
ter swallowing part-way with some of the prey still hanging out-
side, the snake shuts its mouth, curves its backbone back and
forth, and then reopens its mouth while quickly straightening
out the backbone, which causes the head to shoot forward over
more of the prey’s body. Some people believe the snake may dig
through the soil by the same method, but no one has seen this.
CONSERVATION STATUS
These species are not listed as endangered or threatened. Like
many other species that live much of their lives underground,
however, scientists have little information about their numbers
in the wild.
SPECIES
RED-TAILED PIPE SNAKE ACCOUNT
Cylindrophis ruffus
Red-tailed pipe snakes and people: Humans and these snakes have
little contact.
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Aniliidae
One species: False coral snake
(Anilius scytale)
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The false coral snake, the only species in this family, is a
subclass brightly colored, orange, red, or pinkish snake with fifty to sixty
black bands. Each of the bands is two, three, or four scales
order wide. In some members of this species, the black bands are in-
monotypic order complete. In other words, they only reach partway up the sides
suborder of the snake and do not meet at the top of the back. Sometimes,
the individual orange, red, or pinkish scales are outlined in
▲ family black, making the snake look slightly speckled. Its belly is all
red, orange, or pinkish, with no black banding. All scales on
its body are shiny and smooth, which means they have no
ridges, or keels. This nonvenomous (nahn-VEH-nuh-mus)
snake looks somewhat similar to the venomous, or poisonous,
coral snake species that shares its habitat and is therefore
known as a “false” coral snake. Both false coral snakes and coral
snakes, which are in the family Colubridae, are red, orange, or
pink with evenly spaced black bands.
The body of a false coral snake is about the same thickness
from one end to the other, giving the snake an overall tube
shape. Both the head and tail are short. In snakes, the tail be-
gins at the vent, which is a slitlike opening on the underside
of the snake. This tube-shaped body is very similar to that of
the pipe snakes of family Cylindrophiidae, and the false coral
snakes are sometimes called red pipe snakes. At one time, in
fact, the two families were combined into just one family. The
only slight change in the body thickness of the false coral snake
is in its head, which flattens out a bit. The head, which is made
GEOGRAPHIC RANGE
False coral snakes live in eastern Peru, Ecuador, Colombia,
Bolivia, Brazil, French Guiana, southwestern Venezuela, Suri-
name, and Guyana, especially in the Amazon and Orinoco
Basins, which are the areas surrounding the Amazon and
Orinoco Rivers of South America.
HABITAT
This snake spends much of its time in burrows in loose soil.
It lives in rainforests, especially in low-lying areas near streams
or other waterways.
DIET
False coral snakes eat long and narrow vertebrates (VER-
teh-brehts), which are animals with backbones. These include
small snakes, eels, caecilians, and amphisbaenians. Caecilians
(seh-SEE-lee-ens) are salamanderlike animals that live under-
ground. Amphisbaenians (am-fizz-BANE-ee-ens) are small-
headed, short-tailed lizards that also make their homes below
ground.
CONSERVATION STATUS
The World Conservation Union (IUCN) considers the false
coral snake to be Data Deficient, which means that scientists as
yet have too little information to make a judgment about the
threat of extinction. Destruction and other changes to their habi-
tat, however, are probably threatening at least some populations.
Books
Burnie, David, and Don Wilson, eds. The Definitive Visual Guide to the
World’s Wildlife. New York: DK Publishing, 2001.
Grace, Eric, ed. Snakes. San Francisco: Sierra Club Books for Children,
1994.
Greene, H. W. Snakes: The Evolution of Mystery in Nature. Berkeley: Uni-
versity of California Press, 1997.
Web sites
“Family Aniliidae.” EMBL (European Molecular Biology Laboratory)
Reptile Database. http://www.embl-heidelberg.de/uetz/families/Aniliidae
.html (accessed on September 28, 2004).
Lovera, A. “Anilius scytale (false coral snake, pipe snake, and red pipe
snake).” Animal Diversity Web. http://animaldiversity.ummz.umich.edu/
site/accounts/information/Anilius_scytale.html (accessed on February
2, 2005).
“Pipe Snake (Anilius scytale). Animal Planet.com. http://animal.discovery
.com/fansites/jeffcorwin/carnival/slithering/pipesnake.html (accessed on
February 2, 2005).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Xenopeltidae
Number of species: 2 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The two species of sunbeam snakes—the common sunbeam class
snake and the Hainan sunbeam snake—are among the world’s subclass
most beautiful snakes. Their metallic-looking bodies shine dif-
ferent colors depending on how light bounces off them. When order
a sunbeam snake is in the shade, its back looks dark purplish monotypic order
brown or black, but when it slithers out into the sun, the large
suborder
scales on its back and head erupt into a wave of color. Like a
raindrop can bend sunlight to create a rainbow, this snake has ▲ family
scales that reflect sunlight into many colors. This property is
called iridescence (IH-rih-DEH-sense). In fact, another com-
mon name for this snake is the iridescent earth snake. Young
snakes, which are also iridescent, often have a white patch, or
collar, on the upper neck.
Adults have slightly flattened bodies that are white, light gray,
or light yellow on the bottom. The light color also extends up
onto the lip scales. Sunbeam snakes have very small eyes on a
head that is about the same diameter as the neck, so the head
is not as obvious as it is in vipers, pythons, and many other
snakes. The head flattens out toward the snout, giving it a wedge
shape suited for digging. The skeleton also has some interest-
ing features. The bone in the front of the upper jaw has teeth
where most snakes do not. The snake’s teeth are also all hinged
at the base, rather than more firmly attached to the jaw bone,
so they can wiggle back and forth a bit without falling out.
Adults usually reach about 2 to 3 feet (0.6 to 0.9 meters) in
length. The tail makes up about one-tenth of the body’s total
GEOGRAPHIC RANGE
Sunbeam snakes live in southern China
and Southeast Asia from the Nicobar and An-
“OLD” SPECIES daman islands west of Thailand to the Philip-
Scientists sometimes refer to some pines and south through much of Indonesia.
species, such as the sunbeam snakes, as
being relicts (REH-lihkts). Relict species are HABITAT
those that now live in a much smaller area Sunbeam snakes spend at least part of
than they once did. Typically, they have their time underground, hidden in leaves or
been on Earth for a very long time under trash. They live in humid forests, as
compared to other similar animals and well as rice paddies, farm fields, parks, and
have a set of features—usually something gardens next to the woods. People rarely see
in the skeleton—that is similar to that seen them deep in the forests, which may mean
in ancient animals, many of which are they do not travel there, but it may also sim-
known only from their fossils. In some ply mean people usually overlook them in
cases, relicts now live in widely separated that habitat.
areas, because the species in between
died out over the years. DIET
Scientists have only studied the diet of the
common sunbeam snake, which eats lizards,
frogs, and snakes, as well as small mammals and birds. The snake
is a very fast eater, swallowing its prey more quickly than most
other snakes can. Scientists have not studied the other species.
CONSERVATION STATUS
These snakes are not listed as endangered or threatened.
SPECIES
ACCOUNT COMMON SUNBEAM SNAKE
Xenopeltis unicolor
▲
Class: Reptilia
Order: Testudines
Family: Loxocemidae
One species: Neotropical sunbeam
snake (Loxocemus
family C H A P T E R bicolor)
DIET
This snake will eat small mammals and adult and young
lizards, including whip-tailed lizards. It also eats the eggs of
black and green iguanas and olive Ridley seaturtles. The snake
apparently crawls into the lizard and turtle nests, wraps its body
around the eggs, then moves in with its head to swallow them
whole. In captivity, the snakes will sometimes bite into the eggs,
but then swallow the entire egg. A snake may eat several eggs,
sometimes more than two dozen, at one time.
CONSERVATION STATUS
This species is not listed as endangered or threatened.
Books
Burnie, David, and Don Wilson, eds. The Definitive Visual Guide to the
World’s Wildlife. New York: DK Publishing, 2001.
Greene, H. W. Snakes: The Evolution of Mystery in Nature. Berkeley:
University of California Press, 1997.
McDiarmid, R. W., J. A. Campbell, and T. Touré. Snake Species of the
World. Vol. 1. A Taxonomic and Geographic Reference. Washington, DC:
The Herpetologists’ League, 1999.
Savage, J. M. The Amphibians and Reptiles of Costa Rica. Chicago:
University of Chicago Press, 2002.
Wilson, L. D., and J. R. Meyer. The Snakes of Honduras. 2nd ed.
Milwaukee: Milwaukee Public Museum, 1985.
Web sites
“New World Sunbeam Snake.” Vida Preciosa International Inc.
http://www.vpi.com/5VPIBreeders/NewWorldSunbeamSnake/
NewWorldSunbeamSnake.htm (accessed on September 11, 2004).
“Mexican Burrowing Python, Loxocemus.” Glasgow Zoopark. http://www
.glasgowzoo.co.uk/articles/coldblooded/mexburrowingpyth.php (accessed
on September 11, 2004).
“Mexican Burrowing Snake.” Utah’s Hogle Zoo. http://www.hoglezoo
.org/animals/view.php?id=42 (accessed on September 11, 2004).
Other sources
“Convention on International Trade in Endangered Species of Wild Fauna
and Flora.” http://www.cites.org (accessed on September 9, 2004).
▲
Class: Reptilia
Order: Squamata
Family: Boidae
Number of species: 41 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Boas come in many sizes, from small to very large. The adults
of some species grow to less than 1 foot (about 0.3 meters) in
subclass
length, but some are immense. The boa constrictor (kun-
order STRIK-tuhr), for example, reaches nearly 14 feet (4.3 meters)
monotypic order in length, and the green anaconda can grow to 25 feet (7.7 me-
ters) in length and 300 pounds (136 kilograms). Among all the
suborder boa species, females are usually larger than males.
▲ family The boas are split into two subfamilies. One includes the sand
boa, rubber boa, rosy boa, and eleven other species, none of which
grows to much more than 4 feet (1.2 meters) in length. They all
have small eyes, narrow heads on thick necks, large scales on the
end of their snouts, and short tails. The tail in a snake is the part
of the body behind the vent, a crosswise opening on the belly side
of the snake and toward the rear of the animal. The other sub-
family includes the anacondas, boa constrictors, and other mostly
larger snakes. The smallest is the Abaco boa, which reaches just
31.5 inches (81 centimeters) in length, and the largest is the green
anaconda, which can be about ten times as long. Members of this
subfamily have large heads on smaller necks, large eyes, and long
tails. The anacondas are different in that they have distinctively
soft and loose skin.
Depending on the species, boas may be red, orange, yellow,
green, brown, or gray and may or may not have patterns of
blotches or spots on their backs. Some have scales that shine
in different colors when the light strikes them in certain ways,
and, in a few, the color of the skin changes completely from
GEOGRAPHIC RANGE
Boas live in many places around the world, including South
America, Central America, North America, Europe, Africa, and
Asia. They are also present in New Guinea and on many is-
lands throughout their range.
HABITAT
From fields to forests and marshes to deserts, boas live in
many different habitats. Some of the sand boas make their
homes in deserts, while others, like the viper boas, live in wet
forests. Some species prefer warm climates, but others are able
to exist in very cold areas, like southern Mongolia in Asia. The
boa constrictor is unusual in that it can survive well in a wide
variety of habitats, from deserts to rainforests in warmer cli-
mates and also grasslands in cooler areas.
DIET
While boas may spend some time slinking through their
habitats looking for animals to eat, most of them are ambush
hunters, which means that they find a good spot, wait mo-
tionless for a prey animal to wander by, and then strike out to
grab it. The heat sensors on their faces help them “see” the heat
coming from the prey, which helps them to hunt at night. The
sand boas ambush prey by burying themselves in the sand and
waiting for lizards or small mammals. Amazon tree boas coil
around tree branches to ambush birds, and Puerto Rican boas
sit still in the entrances to caves and watch for bats. Green ana-
condas, which are also called water boas, often lurk underwa-
ter until a passing fish or other animal comes within striking
distance. Members of the boa family are constrictors, which
means that the snake will kill its prey by looping its body
around the animal and squeezing, cutting off the animal’s air
until it is dead. While most boas eat small mammals, birds, or
reptiles, the green anaconda and a few of the giant species eat
quite large animals, including deer and crocodilelike caimans
Boas 343
(KAY-muhns). Some reports, although ex-
tremely rare, indicate that green anacondas
have killed and eaten humans.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), one
species is Endangered, facing a very high risk of extinction in
the wild in the near future. In addition, four are Vulnerable,
which means that they face a high risk of extinction in the wild
in the near future, and two are Near Threatened and are at risk
of becoming threatened with extinction in the wild in the future.
Boas 345
Boa constrictor (Boa constrictor)
SPECIES
ACCOUNTS BOA CONSTRICTOR
Boa constrictor
Diet: Boa constrictors usually dine on small mammals, like rats and
squirrels, but also on birds, iguanas (ee-GWA-nuhs), and other large
lizards. Large boas, which do most of their hunting on the ground,
sometimes eat bigger animals, such as porcupines. Young boas are
much more likely than adults to hunt for prey in trees.
Boas 347
Emerald tree boa (Corallus caninus)
Geographic range: The emerald tree boa lives in the northern half
of South America, near the Amazon River.
Boas 349
Green anaconda (Eunectes murinus)
GREEN ANACONDA
Eunectes murinus
Habitat: Also known as the water boa, the green anaconda is often
found in freshwater marshes, swamps, ponds, and slow-moving
streams or along their shores. The young often climb onto low
branches along the water’s edge.
Boas 351
Cleave, Andrew. Snakes and Reptiles: A Portrait of the Animal World.
New York: Magna Books, 1994.
de Vosjoli, Philippe, Roger Klingenberg, and Jeff Ronne. The Boa
Constrictor Manual. Santee, CA: Advanced Vivarium Systems, 1998.
Greene, Harry W. Snakes: The Evolution of Mystery in Nature. Berkeley:
University of California Press, 1997.
Lamar, W. The World’s Most Spectacular Reptiles and Amphibians.
Tampa, FL: World Publications, 1997.
Martin, James. Boa Constrictors. Minneapolis, MN: Capstone Press,
1996.
Minton, Sherman A., and Madge Rutherford Minton. Giant Reptiles. New
York: Scribners, 1973.
Murphy, John C., and Robert W. Henderson. Tales of Giant Snakes: A
Historical Natural History of Anacondas and Pythons. Malabar, FL:
Krieger Publishing, 1997.
O’Shea, Mark. A Guide to the Snakes of Papua New Guinea. Port
Moresby, Papua New Guinea: Independent Publishing, 1996.
Pope, Clifford Millhouse. The Giant Snakes: The Natural History of the
Boa Constrictor, the Anaconda, and the Largest Pythons, Including
Comparative Facts about Other Snakes and Basic Information on
Reptiles in General. New York: Knopf, 1961.
Stafford, Peter J., and Robert W. Henderson. Kaleidoscopic Tree Boas:
The Genus Corallus of Tropical America. Malabar, FL: Krieger, 1996.
Stebbins, Robert C. A Field Guide to the Western Reptiles and Amphibians:
Field Marks of All Species in Western North America, Including Baja
California. 2nd ed. Boston: Houghton Mifflin, 1985.
Tolson, P. J., and R. W. Henderson. The Natural History of West Indian
Boas. Taunton, U.K.: R & A Publishing, 1993.
Web sites:
“Anaconda.” Nashville Zoo. http://www.nashvillezoo.org/ anaconda.htm
(accessed on September 17, 2004).
“Boa constrictor.” Enchanted Learning.com. http://www.enchantedlearning
.com/subjects/reptiles/snakes/Boa.shtml (accessed on September 17,
2004).
“In the Dark.” Animal Planet.com. http://animal.discovery.com/
convergence/snakes/dispatches/dispatch2.html (accessed on Septem-
ber 17, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Pythonidae
Number of species: 32 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
Some of the largest snakes in the world are pythons. One, class
the reticulated python, even holds the world’s record for the
subclass
longest wild snake at 33 feet (10.1 meters). That particular
snake was killed in 1912 in Sulawesi, also known as Celebes, order
in Indonesia. Besides the reticulated python, however, only two monotypic order
other pythons grow to be longer than 20 feet (6.1 meters). In
fact, the pygmy pythons of Australia are less than 2 feet suborder
(61 centimeters) long when full grown. ▲ family
Pythons look much like boas. They both have cat’s-eye pupils
and little claw-like bits of bone, known as spurs, on each side
of the vent, which is the slitlike opening on the belly side of
the snake. They both also have heat vision and can “see” heat
with little pits on the scales of their lips. Pythons and boas dif-
fer, however, in the location of these pits. In boas, they fall be-
tween scales, but a python’s pits are in the middle of the scales.
Both use the heat sensors to help them locate prey or food an-
imals. Another major difference between the pythons and boas
is that all pythons lay eggs, while all but three species of boas
give birth to baby snakes.
Some pythons are almost completely one color, but many
have patterns of blotches or bands on their backs. Often, the
snake’s scales are iridescent (IH-rih-DEH-sent), which means
that they shine different colors depending on how the light hits
them. A number of these snakes, including the Papuan python,
can actually change color. This species can switch from having
a bright yellow body and light gray head to completely dark
brown from head to tail.
Pythons 353
GEOGRAPHIC RANGE
Pythons are found in southern Asia;
southeastern China and Southeast Asia; the
Philippines; Papua, New Guinea, and In-
donesia; and Australia. They also live in the
central and southern region of Africa, which
SEVEN NEW PYTHON SPECIES is known as Sub-Saharan Africa.
In 2000 and 2001, the number of python
HABITAT
species grew by seven. The seven new
species resulted not when someone found Depending on the species, pythons may live
a new snake in the field, but when scientists in thick forests, open forests, rainforests, rocky
decided that they had wrongly lumped and scrubby areas high on hillsides, deserts,
those seven species in with other python grasslands, swamps, or other freshwater areas.
species. Once they were removed and given Some stay on land all their lives, while others
new species names, the python family grew spend much of their time climbing in trees. A
from twenty-five species to thirty-two. As few survive quite well in the desert, but oth-
studies into this family continue, scientists ers prefer the wetter areas, living in rainforests,
expect that they may find more species or in some cases actually in a lake or other wa-
hidden inside the thirty-two, and the python ter area for up to six months a year.
family will grow yet again.
DIET
Pythons are meat eaters and mostly feed
on mammals and lizards, although some may take an occasional
bird, and a few enjoy other species of snakes. They may crawl
around looking for prey animals, but more often than not, they
hunt by ambush. To ambush a prey, the snake remains still and
waits for an animal to happen by and then lashes out to grab it.
Although it is very, very rare, some of the largest python
species, including reticulated, African, and Indian pythons,
have been known to coil around and then eat humans.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), Ram-
sey’s python of Australia is Endangered, which means that it
faces a very high risk of extinction in the wild. The Asiatic rock
python is listed as Near Threatened, which means that it is
likely to qualify for a threatened category in the near future.
The U.S. Fish and Wildlife Service also lists a certain group,
called a subspecies, of the Indian python as Endangered, or in
danger of extinction throughout all or a significant portion of
its range. Overcollecting is a major problem for these snakes,
and many countries now have strict rules in place to protect
the pythons.
Pythons 355
Black-headed python (Aspidites melanocephalus)
SPECIES
ACCOUNTS BLACK-HEADED PYTHON
Aspidites melanocephalus
Pythons 357
Green python (Morelia viridis)
GREEN PYTHON
Morelia viridis
Geographic range: The green python lives in New Guinea and sev-
eral nearby islands. A small group also makes its home on the Cape
York Peninsula of far northeastern Australia.
Habitat: The green python, which is also known as the green tree
python, lives in forests, often climbing up and through tree branches.
Green pythons and people: Some people hunt this snake for its meat.
Pythons 359
Reticulated python (Python reticulatus)
RETICULATED PYTHON
Python reticulatus
Books
Barker, David G., and Tracy M. Barker. Pythons of the World. Vol. 1.
Australia. Lakeside, CA: Advanced Vivarium Systems, Inc., 1994.
Brazaitis, P., and M. Watanabe. Snakes of the World. New York: Crescent
Books, 1992.
Cleave, Andrew. Snakes and Reptiles: A Portrait of the Animal World.
New York: Magna Books, 1994.
Cogger, Harold G. Reptiles and Amphibians of Australia. Sydney, Australia:
Reed New Holland, 2000.
Pythons 361
Greene, Harry W. Snakes: The Evolution of Mystery in Nature. Berkeley:
University of California Press, 1997.
Lamar, W. The World’s Most Spectacular Reptiles and Amphibians.
Tampa, FL: World Publications, 1997.
Mattison, Chris. Snake: The Essential Visual Guide to the World of
Snakes. New York: DK Publishing Inc., 1999.
McDonald, Mary Ann. Pythons. Minneapolis, MN: Capstone Press, 1996.
Minton, Sherman A., and Madge Rutherford Minton. Giant Reptiles. New
York: Charles Scribner’s Sons, 1973.
Murphy, John C., and Robert W. Henderson. Tales of Giant Snakes: A
Historical Natural History of Anacondas and Pythons. Malabar, FL:
Krieger Publishing Company, 1997.
O’Shea, Mark. A Guide to the Snakes of Papua New Guinea. Port
Moresby, Papua, New Guinea: Independent Publishing Group, 1996.
Pope, Clifford Millhouse. The Giant Snakes: The Natural History of
the Boa Constrictor, the Anaconda, and the Largest Pythons, Including
Comparative Facts About Other Snakes and Basic Information on
Reptiles in General. New York: Alfred A. Knopf, 1961.
Torr, Geordie. Pythons of Australia: A Natural History. Sydney, Australia:
University of New South Wales Press, 2000.
Web sites
“Boas and Pythons.” Singapore Zoological Gardens. http://www
.szgdocent.org/cc/c-boa.htm (accessed on September 17, 2004).
“Green Tree Python.” WhoZoo. http://www.whozoo.org/Intro98/jennglaz/
jennglaz21.htm (accessed on September 17, 2004).
“Indian Python.” Bagheera in the Wild. http://www.bagheera.com/
inthewild/van_anim_python.htm (accessed on September 17, 2004).
“Pythons, Boas, and Anacondas: What’s the Difference?” San Diego Zoo.
http://www.sandiegozoo.org/animalbytes/t-python.html (accessed on
September 20, 2004).
“Royal Python.” Canadian Museum of Nature. http://www.nature.ca/
notebooks/english/python.htm (accessed on September 17, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Bolyeriidae
One species Splitjawsnake
(Casarea dussumieri)
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The splitjaw snake has an upper jaw bone split into front class
and back halves that are hinged together at a point just below subclass
the eye. With this unusual split in the jaw, the bone holding
the upper teeth in the front of the mouth can bend up and order
down, while the bone holding the back teeth can stay in place. monotypic order
No other bird, mammal, reptile, amphibian, or fish has such a
suborder
strangely jointed jaw. For many years, this snake was consid-
ered to be a member of the boa family, but its odd jaw was so ▲ family
unusual that scientists felt it should be in its own family. De-
spite its listing in its own family, the splitjaw snakes often go
by common names that still include the word “boa.”
Two members of this family existed in the 20th century, but
only one has survived to enter the 21st century. The smooth-
scaled splitjaw, also known as the smooth-scaled Round Island
boa, is now believed to be extinct. The other species, the keel-
scaled splitjaw, still exists today. The main difference between
the two snakes is the presence or absence of small ridges, or
keels, on the scales. Only the keel-scaled splitjaw has the ridges.
In the splitjaws, as in other snakes, the ridges make the skin
look a bit dull. Smooth scales, on the other hand, usually give
snakes a shiny appearance.
The keel-scaled splitjaw is a thin snake with six-sided, or
hexagonal (HEHK-SAE-guh-nuhl), scales running down its
back. In many snake species, the back scales overlap, but the
splitjaw’s back scales barely touch each other, if at all. The snake
has a long tail that makes up at least one-quarter of its entire
GEOGRAPHIC RANGE
Also known as the Round Island casarea boa, the keel-scaled
splitjaw lives only on Round Island, which is located in the In-
dian Ocean east of Madasgascar and just northwest of the is-
land of Mauritius. At one time, this snake made its home on
other small islands near Round Island and on the much-larger
Mauritius, but now they live on just the one island. Round Is-
land covers only 374 acres (151 hectares) and was created from
lava ejected from a volcano. In the 1960s and 1970s, Round Is-
land also had another species of splitjaw. During that period,
observers on the island discovered a smooth-scaled splitjaw and
watched the snake over a two-decade period. They were able
to identify the snake from sighting to sighting by a distinctive
scar on its body. They saw that lone snake on Round Island for
the last time in 1975, and no one has ever seen a smooth-scaled
splitjaw again. The discovery of the living snake was quite for-
tunate, because scientists would otherwise have never known
of this species. While fossils of many other living and extinct
snake species have been found, no one has ever found and iden-
tified a fossil from the smooth-scaled splitjaw.
HABITAT
The keel-scaled splitjaw prefers to live in the lush palm-
covered rainforest of Round Island. Because much of the rain-
forest is now gone, however, the snake is surviving among
stumps, scraggly bushes, and what few areas of thick forest it
can find. The snake stays underground much of the time and
therefore relies on proper soil conditions. Unfortunately, hu-
in 1982. The female laid eggs. Since then, other female keel-
scaled splitjaws have laid eggs, too. No one has observed the
snakes mating in the wild, but in captivity, they seem to mate
most successfully from March to July and lay eggs from May
to October. A female typically lays three to eleven soft-shelled
eggs at a time, possibly laying them in a hidden spot, such as
within a pile of leaves or inside a hollow tree trunk. Females
may stay with the eggs for a while. When they hatch in about
three months, the young are bright orange.
CONSERVATION STATUS
The World Conservation Union (IUCN) and the U.S. Fish
and Wildlife Service consider the Round Island casarea split-
jaw to be Endangered, or facing a very high risk of extinction
in the wild throughout all or a significant portion of its range.
It once lived on the nearby and much larger Mauritus Island,
Books
Burnie, David, and Don Wilson, eds. The Definitive Visual Guide to the
World’s Wildlife. New York: DK Publishing, 2001. Page 379.
Day, David. The Doomsday Book of Animals. London: London Editions
Limited, 1981.
Greene, Harry W. Snakes: The Evolution of Mystery in Nature. Berkeley:
University of California Press, 1997.
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Tropidophiidae
Number of species: 25 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The woodsnakes and spinejaw snakes are small-to-medium- class
sized snakes that resemble boas. Colors range from gray to
subclass
brown, and most have faint blotches or stripes. Some have
smooth scales, and others have scales with ridges, or keels. order
Among those with smooth scales, the Oaxacan dwarf boa has monotypic order
scales that shine different colors depending on how the light
hits them. Scales that do this are known as iridescent (IH-rih- suborder
DEH-sent). On the other hand, some members of this family ▲ family
have dull-looking scales with noticeable keels. The Cuban black
and white dwarf boa even has scales that change color from
darker during the daytime to lighter at night.
The smallest member of this family is the Cuban dusky trope,
which reaches at most 12 inches (30 centimeters) long. The
largest is the dusky dwarf boa, which can grow to 41 inches
(104 centimeters) in length.
Some people believe that this family should be split in two
with one keeping the name Tropidophiidae and the other falling
under a new family called Ungaliophiidae. Occasionally, some
books will place these snakes under the family Boidae, but al-
though some have the common name of dwarf boas, they are
not actually boas.
GEOGRAPHIC RANGE
They are found from Brazil to Mexico and in the West In-
dies. Some species are found in both Malaysia and Borneo.
CONSERVATION STATUS
This species is not listed as endangered or threatened. One
species, the Navassa woodsnake, was noted as extinct in the
1990s, likely due to changes in its habitat and deaths from mon-
goose attacks. A mongoose is a ferretlike, meat-eating animal
that is an excellent hunter.
SPECIES
ACCOUNT SOUTHERN BROMELIAD WOODSNAKE
Ungaliophis panamensis
Conservation status: Scientists know so little about this snake, in- Much of the information about
southern bromeliad woodsnakes
cluding how many of them live in the wild, that they cannot make
comes from captive snakes
any statements about its conservation status. ■ rather than those in the wild.
(Illustration by Emily Damstra.
Reproduced by permission.)
FOR MORE INFORMATION
Books
Brazaitis, P., and M. Watanabe. Snakes of the World. New York: Cres-
cent Books, 1992.
Burnie, David, and Don Wilson, eds. The Definitive Visual Guide to the
World’s Wildlife. New York: DK Publishing, 2001.
Crother, Brian I., ed. Caribbean Amphibians and Reptiles. San Diego:
Academic Press, 1999.
Duellman, William E., ed. The South American Herpetofauna: Its Origin,
Evolution and Dispersal. Monograph of the Museum of Natural History,
Number 7. Lawrence: The University of Kansas, 1979.
Greene, Harry W. Snakes: The Evolution of Mystery in Nature. Berkeley:
University of California Press, 1997.
Lamar, W. The World’s Most Spectacular Reptiles and Amphibians.
Tampa, FL: World Publications, 1997.
Web sites
“Talking Taino: Lizards and Snakes.” Times of the Islands. Summer 2004.
http://www.timespub.tc/Natural%20History/Archive/Summer2003/
ttsnake.htm (accessed on September 15, 2004).
▲
Class: Reptilia
Order: Squamata
Family: Acrochordidae
Number of species: 3 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
Also known as wart snakes or elephant-trunk snakes, the file class
snakes have baggy skin that lies in loose folds. The skin is cov- subclass
ered with tiny scales and small, bristly outgrowths that make
the skin seem quite rough. This rough skin looks rather like order
the surface of a file, and some say it also looks as if it is cov- monotypic order
ered with small warts; it is the appearance of their skin that suborder
gives them the common name “file” snakes. Although for many
years people thought that the little file snake was venomous ▲ family
(VEH-nuh-mus), or poisonous, and dangerous to humans, sci-
entists now know that none of the three file snake species, or
types, has a bite that can harm a person.
File snakes spend nearly their entire lives in the water. A file
snake has both its eyes and its nostrils, or nose holes, located
on the top of its short head, so it can breathe the air and see
above the water surface while the rest of the body remains un-
derwater. The nostrils also have little valves, or flaps, that can
close up when the snake dips completely below the water’s sur-
face. The tail is somewhat flattened from side to side and helps
the snake swim. Male and female file snakes look very much
alike, except that the females have slightly larger heads, thicker
bodies, and shorter tails. The tail on a snake is the part of the
body that extends back from a slit on the belly. File snakes range
in length from about 20 to 76 inches (0.5 to 2 meters). The lit-
tle file snake is the smallest member of the family, averaging 20
to 28 inches (51 to 71 centimeters) in length but sometimes
reaching 40 inches (1 meter). The Arafura file snake grows to
GEOGRAPHIC RANGE
The file snakes live from India to South-
east Asia and Australia. They inhabit north-
A DIFFERENT WAY TO SHED ern Australia, the Solomon Islands east of
A little file snake sheds its skin New Guinea, Malaysia, and Indonesia.
differently from the typical land-living
snake, which turns its skin inside out as it HABITAT
scoots out of the old skin. Instead, the little The file snakes usually live in warm, shal-
file snake first wriggles its body free of its low waters. The Arafura and Java file snakes
loose skin, so that the skin is separate from live in freshwater streams; lagoons, or shal-
the body but still in place around it. Then low bodies of saltwater near the sea; and
it works its way free, sometimes knotting rivers. In the dry season, the Arafura file
its body to help it escape from the old skin. snake is also found in billabongs (BILL-uh-
The skin remains right side out. bongs), which are dried-up streambeds. Dur-
ing the rainy season, it will slither into
flooded grasslands. The Java file snake, on
the other hand, occasionally swims into the salty ocean water
for short periods of time. Little file snakes can live in both fresh-
water and saltwater areas, from the ocean to swamps near the
coastline and to inland rivers, sometimes up to 6 miles (9.6
kilometers) out to sea and in water up to 66 feet (20 meters)
deep. Little file snakes have salt glands, small groups of cells
that may help them control the amount of salt in their bodies.
Salt glands are also seen in many other animals that live in salty
waters. Scientists have not studied this gland in detail, how-
ever, so they are unsure how important it is to the snake’s sur-
vival in saltwater.
DIET
The three file snake species eat mostly fishes, and they do
not seem to care whether the meal is alive or dead when they
find it. The little file snake also eats crustaceans (krus-TAY-
shuns). Crustaceans include shelled animals, such as shrimp
and crayfish. The Java file snake adds freshwater eels to its diet
of mainly catfishes. The Arafura file snake can eat very large
fishes. According to one report, a snake that measured
44.5 inches (113 centimeters) in length ate a 19-inch-long
(48-centimeter-long) fish—nearly half the snake’s size—in just
two minutes.
CONSERVATION STATUS
File snakes are not considered threatened, but some popula-
tions may have low numbers. Habitat loss, as well as habitat dam-
age from water pollution, or dirtying and poisoning of water,
may hurt their ability to survive into the future. In areas with
large fish populations, however, file snakes can become very nu-
merous. Scientists have counted 100 or more Arafura file snakes
on every 2 acres (0.8 hectare) of some Australian billabongs.
SPECIES
ACCOUNT LITTLE FILE SNAKE
Acrochordus granulatus
Geographic range: The little file snake lives from the western coast
of India through the tropical regions of Southeast Asia (including In-
donesia and the Philippines) to New Guinea and northern Australia.
Diet: The little file snake eats mainly the spiny-finned fishes called
gobies (GO-bees) and other goby-like fishes and crustaceans.
Web sites:
“File Snakes.” Singapore Zoological Gardens Docents. http://www
.szgdocent.org/cc/c-file.htm (accessed on September 10, 2004).
▲
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Viperidae
Number of species: 256 species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class Vipers and pitvipers are mainly known for the pair of short
subclass hollow fangs that usually lie flat in the upper jaw but swing
down when the snake opens its mouth to inject its venom. The
order
members of this family are typically rather thick snakes with
monotypic order large triangular-shaped heads, usually catlike eye pupils, and
suborder short tails. The tail in a snake is the part of the body behind the
vent, a slitlike opening on the belly side of the animal. Those
▲ family snakes that spend much of their time climbing among shrubs
and trees have longer tails. Some vipers and pitvipers have
zigzag, diamond-shaped, or other patterns on their backs, but
for the most part, vipers and pitvipers have no showy colors and
instead simply blend into the background, which often makes
them difficult to spot.
HABITAT
Most members of this family live on land, but some, such as
the cottonmouth, spend a good part of their time in the water.
Vipers and pitvipers make their homes in warm tropical cli-
mates and in cooler temperate climates that have distinct sea-
sons, including cold winters. Temperate species often move
from one habitat to another during the spring, summer, and
fall and then hibernate through the winter. For example, North
America’s eastern massasauga rattlesnake spends the early
spring near wetlands, moves into drier nearby fields for the hot
summer months, and hibernates back near the water in un-
derground burrows made by crayfish or small mammals. Dur-
ing hibernation (high-bur-NAY-shun), the animal enters a state
of deep sleep that helps it to survive the frigid weather.
DIET
Vipers and pitvipers eat mice, rats, and lizards, but they will
also feed on birds, frogs, and other animals. A few of the small-
est species eat locusts, a type of grasshopper.
Vipers and pitvipers are predators (PREH-dih-ters) and use
their venom when hunting prey or sometimes when defend-
ing themselves. The venom attacks the blood system of the
prey, producing burning pain and other symptoms, and later
stopping the heart. A few vipers and pitvipers have venom
that also attacks the nervous system. Some species slowly
slither along looking for prey animals, but others rely on their
camouflage-like colors to hide them until an unsuspecting an-
imal happens by. In either case, the snake lashes out at the
prey animal with great speed, opening its mouth to swing
down its fangs and biting the animal to inject the venom—all
in the blink of an eye. The prey never even sees the snake un-
til it is too late.
CONSERVATION STATUS
According to the World Conservation Union (IUCN), seven
species are Critically Endangered; four species are Endangered;
seven species are Vulnerable, and one species is listed as Data
Deficient. The Critically Endangered species face an extremely
high risk of extinction in the wild, while the Endangered species
face a very high risk, and the Vulnerable face a high risk. Sci-
entists have too little information on those noted as Data De-
ficient to make a judgment about the threat of extinction. The
U.S. Fish and Wildlife Service lists one U.S. and one foreign
SPECIES
ACCOUNTS HORNED VIPER
Cerastes cerastes
Diet: They eat other animals of sandy habitats. These may include
small mammals, lizards, and birds.
Horned vipers and people: Since it hides during the day, people
rarely see the horned viper. It does, however, sometimes bite people,
but the bites are not thought to be that dangerous.
COTTONMOUTH
Agkistrodon piscivorus
Diet: Cottonmouths will eat almost any animals they find. This
includes birds, eggs, living and sometimes dead fishes, frogs, small
alligators and turtles, snakes and other cottonmouths, and mammals.
TIMBER RATTLESNAKE
Crotalus horridus
Diet: They have only six to twenty meals a year, but when they do
eat, they hunt for mammals, and sometimes birds, lizards, frogs, in-
sects, and other snakes.
BLACK-HEADED BUSHMASTER
Lachesis melanocephala
▲
Class: Reptilia
Order: Squamata
Family: Atractaspididae
Number of species: 62 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The African burrowing snakes have small heads, rounded at class
the front. Their heads are no larger in diameter than their necks.
subclass
Only the quill-snouted snake has a head that comes to a point.
The members of this family have small, sometimes very tiny, eyes order
with round pupils. Most have fangs, or long, pointed teeth, at monotypic order
the rear of the mouth, but some have hollow fangs at the front
of the mouth. These front fangs swing out to inject venom, or suborder
poison, into their prey, animals that they hunt for food, or their ▲ family
predators (PREH-duh-ters), the animals that hunt them for food.
These small to medium-sized snakes are long and thin; adults
range in length from about 12 to 40 inches (30 to 102
centimeters), from head to tail tip. Most are black or brown
with a different-colored ring around the neck. A few have bright
stripes. All have smooth scales, instead of the ridged scales seen
in many other snakes.
GEOGRAPHIC RANGE
Most African burrowing snakes live in the central and south-
ern regions of Africa, known as sub-Saharan Africa, but a few
make their homes in Israel or in Jordan.
HABITAT
Just as their name suggests, this group of snakes likes to live
in burrows, or tunnels, underground. They are especially fond
of sandy soils. Some like the damp soil of lowland forests, but
others can live quite well in the drier sands of grasslands and
areas that are almost desertlike.
CONSERVATION STATUS
A few species of African burrowing snake live in very small
areas, but no species is endangered or threatened.
SPECIES
ACCOUNT SOUTHERN BURROWING ASP
Atractaspis bibronii
Books:
Branch, Bill. Field Guide to Snakes and Other Reptiles of Southern Africa.
Sanibel Island, FL: Ralph Curtis Books, 1998.
Lovett, Sarah. Extremely Weird Snakes. Santa Fe, NM: John Muir Publi-
cations, 1999.
Mattison, Chris. The Encyclopedia of Snakes. New York: Facts on File,
1995.
Montgomery, Sy. The Snake Scientist. Boston: Houghton Mifflin, 2001.
Spawls, Stephen, and Bill Branch. The Dangerous Snakes of Africa: Nat-
ural History, Species Directory, Venoms, and Snakebite. Sanibel Island,
FL: Ralph Curtis Books, 1995.
Spawls, Stephen, et al. A Field Guide to the Reptiles of East Africa: Kenya,
Tanzania, Uganda, Rwanda, and Burundi. San Diego: Academic Press,
2002.
▲
Class: Reptilia
Order: Squamata
Family: Colubridae
Number of species: 1,700 species
family C H A P T E R
PHYSICAL CHARACTERISTICS phylum
The colubrids (KAHL-yuh-bruhds) make up the largest class
group of snakes; they include almost 75 percent of all the subclass
world’s snake species, or types of snakes. These snakes come
in many sizes, shapes, and colors. Despite the many differences order
among the snakes in this family, colubrids share a few features. monotypic order
Most have wide scales on their bellies and, usually, nine large suborder
scales on the tops of their heads. Most colubrids also have
glands, or groups of cells, behind each eye. These glands ▲ family
squeeze out a mixture of chemicals that, in some species, oozes
through enlarged back teeth, known as rear fangs. When a col-
ubrid bites down on a prey animal, this venom, or poison, trick-
les into the prey animal; the venom slows down, knocks out,
or kills the animal, which the colubrid then eats. Unlike the
cobras and vipers, whose fast-acting venom can knock out or
kill an animal in moments, the colubrids produce venom that
is not as strong and usually takes many minutes to work. The
boomslangs and a few other species are exceptions to the
rule; they have venom powerful enough to kill humans. An-
tivenin (an-tee-VEH-nuhn), a remedy that neutralizes, or
makes ineffective, the poison of the snake, is available to treat
the bites.
Colubrid snakes range widely in size, with some species
growing to about 6 inches (15.2 centimeters) and others reach-
ing 12 feet (3.7 meters) in length. Depending on the species,
males may be larger than females, or females may be larger than
males.
Colubrids 399
GEOGRAPHIC RANGE
Colubrid snakes occur almost everywhere in the world. The
only places they do not live are Antarctica; the far northern
reaches of Europe, Asia, and North America; and central and
western Australia.
HABITAT
The snakes in this family make their homes in many different
places. Some spend most of their time underground, some climb
into trees and shrubs, some slither about mostly on the ground,
and others live mainly in water. Most of the water-living
colubrids like freshwater habitats, but a few, like the crab-eating
water snake, can live in saltier water. A particularly unusual col-
ubrid is the Southeast Asian flying snake, which not only climbs
trees but also soars from one tree branch to another. These snakes
do not actually fly but instead flatten out their bodies and soar
from a higher branch to a lower one.
DIET
Depending on the species, colubrids may eat mammals,
lizards, baby turtles, frogs and toads, fishes, earthworms, scor-
pions, tarantulas, some insects, and any number of other ani-
mals that will fit in their mouths. Some colubrids will eat almost
anything that comes their way. Others will eat only a handful
of different food items, and a few are extremely picky about
their meals. For example, the rainbow snake dines on eels and
little else, and the egg eaters of Africa swallow only whole bird
eggs. In some species, snakes that eat one type of prey as young-
sters continue eating that type of prey into adulthood. Many
common garter snakes that grow up eating earthworms, for ex-
ample, stick to a mostly earthworm diet as adults.
Colubrids 401
species have fewer young than the larger species. Some of the
smallest colubrids, such as the worm snakes, may lay only three
eggs at a time, while larger species, like mud snakes, may lay
more than thirty eggs. The diamond-backed water snake gives
birth to nearly fifty live young at a time. For some species, the
female’s duties are complete as soon as she gives birth, but for
others, the female will stay near her nest and protect her eggs.
CONSERVATION STATUS
The World Conservation Union (IUCN) lists one species as
Extinct, meaning that none is still alive. Six species are Criti-
cally Endangered, meaning that they face an extremely high
risk of extinction in the wild, and seven are Endangered, mean-
ing that they face a very high risk of extinction. Eight are con-
sidered Vulnerable, meaning that their risk of extinction is high,
and four are Near Threatened, meaning that they may face the
risk of becoming threatened with extinction in the near future.
The U.S. Fish and Wildlife Service lists seven U.S. species and
one foreign colubrid as Threatened.
The danger to most colubrid populations comes from the de-
struction of their habitat, or their preferred living areas, and
their collection for the pet trade, food, or leather. While many
species are finding it hard to survive, the brown tree snake is
doing very well. This slender snake grows to 4.5 to 6.5 feet (1.4
to 2 meters) in length. It is native to Indonesia, New Guinea,
Australia, and the Solomon Islands, but it seems to have hitched
a ride on military ships during World War II to the Pacific is-
land of Guam. Once there, it quickly adapted to its new home
and has since hunted and eaten to extinction several species of
the island’s native birds and lizards.
SPECIES
BOOMSLANG ACCOUNTS
Dispholidus typus
Habitat: This snake spends most of its time crawling among the
branches of trees and shrubs in forests and grasslands.
Colubrids 403
Boomslangs spend most of their
time crawling among the
branches of trees and shrubs in
forests and grasslands. (Bill
Ruth/Bruce Coleman Inc.
Reproduced by permission.)
Geographic range: This snake lives in Canada, the United States, and
Mexico. Some populations live as far south as Florida and northern
Colubrids 405
Mexico, while others live as far north as Canada and
into the southern part of the Northwest Territories.
MILKSNAKE
Lampropeltis triangulum
Colubrids 407
Geographic range: The milksnake lives in North
America, Central America, and South America.
They make their homes throughout much of the
New World, from southeastern Canada through all
but the far western United States, into Mexico,
Central America, and south to Ecuador and north-
ern Venezuela.
Colubrids 409
Habitat: This snake likes drier areas, including
fields and forests.
INDIGO SNAKE
Drymarchon corais
Colubrids 411
Although it lives mainly on land,
the indigo snake often prefers
areas near a water source.
(©Joseph T. Collins/Photo
Researchers, Inc. Reproduced by
permission.)
Diet: The indigo snake eats a variety of animals, including fishes and
frogs, turtles, birds, mammals, and other snakes, including pit vipers.
Behavior and reproduction: Active during the day, this large snake
spends much of its time searching for prey, which it bites at and swal-
lows using its strength and size. Females lay about four to twelve
eggs at a time. When the eggs hatch, the young snakes may be 2 feet
(61 centimeters) long or more.
Indigo snakes and people: People often collect this usually gentle
snake for the pet trade.
Conservation status: Although the IUCN does not consider the in-
digo snake to be threatened, the U.S. Fish and Wildlife Service lists it
as Threatened in the United States. This large snake is popular in the
pet trade. Its habitat is shrinking as people build in these areas. ■
Books:
Branch, Bill. Field Guide to Snakes and Other Reptiles of Southern Africa.
Sanibel Island, FL: Ralph Curtis Books, 1998.
Web sites:
“Eastern Garter Snake.” Iowa Herpetology. http://www.herpnet.net/
Iowa-Herpetology/reptiles/snakes/e.garter_snake.html (accessed on
September 9, 2004).
“Eastern Hognose Snake.” Iowa Herpetology. http:// www.herpnet.net/
Iowa-Herpetology/reptiles/snakes/e.hognose_snake.htm (accessed on
September 9, 2004).
“Eastern Indigo Snake.” University of Georgia Savannah River Ecology
Laboratory. http://www.uga.edu/srel/eastern_indigo_snake.htm (ac-
cessed on September 1, 2004).
“Milk Snake.” Iowa Herpetology. http://www.herpnet.net/Iowa-Herpetology/
reptiles/snakes/eastern_milksnake.html (accessed on September 9,
2004).
Colubrids 413
COBRAS, KRAITS, SEA
SNAKES, AND RELATIVES
Elapidae
▲
Class: Reptilia
Order: Squamata
Family: Elapidae
Number of species: More than 300
species
family C H A P T E R
phylum PHYSICAL CHARACTERISTICS
class The cobras, kraits (KRYTS), sea snakes, death adders, and
other members of this family are venomous (VEH-nuh-mus),
subclass
or poisonous, snakes that vary in length from just 7 inches
order (17.8 centimeters) to 16 feet, 8 inches (5 meters). Despite their
monotypic order many differences, all of the snakes in this family, known as
elapids (EH-luh-puds), are alike in some ways. They each have
suborder two “fixed” fangs, or long, pointed teeth that cannot move, at
▲ family the front of the mouth. These short fangs are always pointed
downward and ready to inject venom. Elapids are mostly thin
snakes with heads that are about the same size around as their
necks and with large scoots, or scales, down the back. Many
cobras are well known for their ability to spread out their necks
into a sort of hood.
Some elapids are brightly colored; others are not. Some have
stripes, but others are just one color. Still others have side-to-
side bands of color. The coral snakes, for example, often have
bright bands of different colors.
GEOGRAPHIC RANGE
The elapids live in Africa, Asia, Australia, the United States
and Mexico, Central America, South America, and the Pacific
and Indian Oceans.
HABITAT
This large family has species that can live in almost any habi-
tat, from deserts and dry grasslands to rainforests and even
CONSERVATION STATUS
The World Conservation Union (IUCN) lists seven species
as Vulnerable, which means that they face a high risk of ex-
tinction in the wild. Two species are Near Threatened, which
means they are at risk of being threatened with extinction in
the future. Causes for the declines in their numbers may in-
clude loss of their habitats, or preferred living areas, and col-
lecting of snakeskins for leather.
SPECIES
NORTH AMERICAN CORAL SNAKE ACCOUNTS
Micrurus fulvius
Habitat: The North American coral snake lives in many areas, in-
cluding deserts and forests and even along the shorelines of lakes and
ponds.
Diet: This snake eats mostly small lizards but sometimes also dines
on frogs and other snakes. It tracks the lizards and snakes by fol-
lowing their scents (SENTS), or smells.
North American coral snakes and people: The coral snake’s venom
is strong enough to kill a human, but antivenin (an-tee-VEH-nuhn)
is available. Antivenin is a substance that neutralizes a snake’s venom,
meaning that it causes the venom to have no bad effect.
KING COBRA
Ophiophagus hannah
Geographic range: The king cobra lives from India through South-
east Asia (the Philippines and into Indonesia).
Habitat: King cobras are animals of the thick jungle and usually
prefer to live near water.
Diet: Their main food items are other snakes, including other ven-
omous species.
King cobras and people: When a king cobra bites a person, it can
inject a dose of venom that can kill.
DEATH ADDER
Acanthophis antarcticus
Diet: The death adder eats mainly small reptiles but also frogs and
small mammals.
Death adders and people: The snake’s venom is very strong and
can kill people. Antivenin is available.
SEA KRAIT
Laticauda colubrina
Habitat: Sea kraits spend most of their lives in the ocean water,
coming ashore only to rest or to lay their eggs. Once in a while, they
may travel into mangrove swamps. Mangroves are tropical trees and
shrubs that form thick masses along coastlines.
Diet: They usually find their food, primarily eels, in coral reefs.
Behavior and reproduction: Most active at night, the sea krait oc-
casionally looks for food in the daytime. In the breeding season, fe-
males leave their saltwater homes to lay up to eighteen eggs at a time
on the seashore.
Sea kraits and people: People are rarely bitten by this gentle snake.
A sea krait’s bite, however, is venomous.
Books:
Branch, Bill. Field Guide to Snakes and Other Reptiles of Southern Africa.
Sanibel Island, FL: Ralph Curtis Books, 1998.
Brazaitis, Peter, and Myrna E. Watanabe. Snakes of the World. New York:
Crescent Books, 1992.
Broadley, Donald G. FitzSimons’ Snakes of Southern Africa. Johannesburg,
South Africa: Jonathan Ball, 1990.
Campbell, Jonathan A., and William W. Lamar. The Venomous Reptiles
of Latin America. Ithaca, NY: Comstock Publishing Associates, 1989.
Cogger, Harold G. Reptiles and Amphibians of Australia. Sydney, Australia:
Reed New Holland, 2000.
Creagh, Carson. Reptiles. Alexandria, VA: Time-Life Books, 1996.
Web site:
“King Cobra.” NationalGeographic.com. http://www.nationalgeographic
.com/kingcobra/index-n.html (accessed on September 9, 2004).
IRAQ LESOTHO
Sandfish Boomslang MALI
Helmeted turtle Boomslang
Nile crocodile
ISRAEL LIBERIA Sandfish
Common chameleon Boomslang
Horned viper Helmeted turtle
Sandfish Nile crocodile MALTA
Common chameleon
IVORY COAST LIBYA
Boomslang Common chameleon MAURITANIA
Helmeted turtle Horned viper Horned viper
Nile crocodile Sandfish Sandfish