Species New to Science

 A new species, †Nannotanyderus granieri sp. nov., belonging to the Tanyderidae (Diptera, Nematocera), from Lower Barremian amber of Bqaatouta (Lebanon), is characterized, described, figured, and its taxononomic position discussed. The possible confusion regarding the attribution of new fossils to either the Tanyderidae or the Psychodidae, in addition to the results of recent molecular phylogenies, have led us to re-evaluate the taxonomic position of the Tanyderidae and to consider it as a subfamily within the Psychodidae. The fossil described herein is a tiny tanyderine sensu nov. species, and the second one belonging to the genus Nannotanyderus from Lebanese amber. A tentative molecular phylogeny of recent Psychodidae and an exhaustive catalogue of fossil Tanyderinae stat. nov. are provided. 

Keywords: • Diptera; • Tanyderidae; • Psychodidae; • Tanyderinae stat. nov.; • Tanyderini; • Nannotanyderini; • Lower Cretaceous; • Lebanon 

 

Abstract

Despite being known from every continent, the geological record of pterosaurs, the first group of vertebrates to develop powered flight, is very uneven, with only a few deposits accounting for the vast majority of specimens and almost half of the taxonomic diversity. Among the regions that stand out for the greatest gaps of knowledge regarding these flying reptiles, is the Afro-Arabian continent, which has yielded only a small number of very fragmentary and incomplete materials. Here we fill part of that gap and report on the most complete pterosaur recovered from this continent, more specifically from the Late Cretaceous (~95 mya) Hjoûla Lagerstätte of Lebanon. This deposit is known since the Middle Ages for the exquisitely preserved fishes and invertebrates, but not for tetrapods, which are exceedingly rare. Mimodactylus libanensis gen. et sp. nov. differs from the other Afro-Arabian pterosaur species named to date and is closely related to the Chinese species Haopterus gracilis, forming a new clade of derived toothed pterosaurs. Mimodactylidae clade nov. groups species that are related to Istiodactylidae, jointly designated as Istiodactyliformes (clade nov.). Istiodactyliforms were previously documented only in Early Cretaceous sites from Europe and Asia, with Mimodactylus libanensis the first record in Gondwana.

Systematic palaeontology

Pterosauria Kaup, 1834.

Pterodactyloidea Plieninger, 1901.

Ornithocheiroidea Seeley, 1870 sensu Kellner (2003).

Pteranodontoidea Marsh, 1876 sensu Kellner (2003).

Lanceodontia Andres et al., 2014.

Istiodactyliformes clade nov.

Branch-based definition: The most inclusive clade containing Istiodactylus latidens, but not Anhanguera blittersdorffi.

Diagnosis: Slender-built lanceodontian pterodactyloids with the following synapomorphies: mandibular rostral end pointed, teeth confined to the anterior half of the jaws, and labiolingually compressed crowns with a cingulum.

Included taxa: Istiodactylidae, Mimodactylidae, and Hongshanopterus lacustris.

Mimodactylidae clade nov.

Branch-based definition: The most inclusive clade containing Mimodactylus libanensis gen. et sp. nov., but not Istiodactylus latidens, Ikrandraco avatar, and Anhanguera blittersdorffi.

Diagnosis: Istiodactyliforms with cone-shaped teeth, crowns with a slight labiolingual compression, and sternal articular surface of the coracoid slightly concave.

Included species: Haopterus gracilis and Mimodactylus libanensis gen. et sp. nov.

Mimodactylus libanensis gen. et sp. nov.

Etymology: Mimodactylus, from the acronym MIM (Mineral Museum) for the museum housing the specimen, in recognition of both the museum and the wishes of the anonymous philanthropist who facilitated the acquisition of the specimen thus keeping it in Lebanon, and the Greek ‘dactylos’ (δάκτυλος), meaning digit; libanensis from Lebanon, where the specimen was found.

Holotype: Almost complete skeleton, including the skull and lower jaw, housed at the Mineral Museum (MIM) of Beirut, Lebanon, MIM F1. Cast at the University of Alberta, Edmonton and Museu Nacional/UFRJ (MN 7216-V).

Locality and horizon: Hjoûla Lagerstätte of the Sannine Limestone (late Cenomanian), near the town of Hjoûla located 35 km NNE of Beirut and 10 km inland from Jbail, Lebanon.

Diagnosis: Mimodactylid with the following autapomorphies: humerus with a rectangular deltopectoral crest; humerus smaller than half the length of the second phalanx of the wing finger (hu/ph2d4 < 0.5). This species can be further distinguished from other ornithocheiroid pterodactyloids by the following combination of characters: discrete palatal ridge; 11 and 10 cone-shaped teeth on each side of the upper and lower jaws, respectively; scapula slightly longer than coracoid; humerus much longer than femur (hu/fe ~1.3); deltopectoral crest extends for around 40% of the humerus shaft length (see Supplementary Information for further details and measurements).

...

Alexander W. A. Kellner, Michael W. Caldwell, Borja Holgado, Fabio M. Dalla Vecchia, Roy Nohra, Juliana M. Sayão and Philip J. Currie. 2019. First Complete Pterosaur from the Afro-Arabian Continent: Insight Into Pterodactyloid Diversity. Scientific Reports. 9, 17875. DOI: 10.1038/s41598-019-54042-z  

twitter.com/pterosaurios/status/1200371986490384390

   

 

ABSTRACT

The Upper Cretaceous (Cenomanian) limestone quarry of Haqel, Lebanon, is home to one of the largest diversities of fossil actinopterygians in the Mesozoic, particularly of pycnodontiform fishes. Here, we describe a pycnodontiform fish, Flagellipinna rhomboides, gen. et sp. nov., from this locality based on four specimens. It is considered a member of the derived family Pycnodontidae due to the presence of a postparietal process. This taxon is distinct from other pycnodontids due to its diamond-shaped body, whip-like dorsal fin, postcloacal scales with forward-pointing spines, and acute anterior profile with a concave slope, giving it a ‘hunchback’ appearance. The prognathous snout armed with molariform teeth suggests that this pycnodont preyed on a variety of shelled animals from crevices. The smallest specimen is distinct in that it has a larger orbit size, no spines on the contour scales, poorly ossified skull roof bones, a notochord partially covered by arcocentra, and lacks whip-like filament on the dorsal fin, which suggest that it is a juvenile/subadult. The differences between the juvenile/subadult and other larger specimens suggest a change in ecological niche occupation during ontogeny, going from a generalized forager that lived in complex, reef habitats to moving into deeper waters to feed from crevices on the reef edge. These findings provide a more complete picture of the possible life history strategies that pycnodontiforms may have used in order to exploit different resources throughout their lives.

SYSTEMATIC PALEONTOLOGY

Class OSTEICHTHYES Huxley, 1880 

Subclass ACTINOPTERYGII Cope, 1887 

Series NEOPTERYGII Regan, 1923 

Order PYCNODONTIFORMES Berg, 1937 

Family PYCNODONTIDAE sensu Nursall, 1996 

FLAGELLIPINNA, gen. nov.

Age— Early late Cenomanian, Late Cretaceous.

Type Species— Flagellipinna rhomboides, sp. nov.

Etymology— The name is a combination of the Latin words ‘flagellum’ (whip) and ‘pinna’ (fin), which refers to the whip-like dorsal fin present in this genus.

FLAGELLIPINNA RHOMBOIDES, sp. nov.

Diagnosis— Small pycnodontid fish with a deep, rhomboid body shape. Anterior profile of the fish is extremely steep, being sloped at a mean 57.3° angle in relation to the vertebral column. Dorsal fin has a whip-like filament. Dorsal and anal pterygiophores inserted very deeply into the body. Dorsal and anal fins falcate anteriorly and become progressively strap-like posteriorly. Ventral apex present anterior to the insertion of anal fin. Two dentalosplenial (dentary) teeth are broad and incisiform, and the anterior (mesial) premaxillary tooth is bicuspid. Skull dorsoventrally flattened and obliquely oriented, with an elongate snout. Paired preparietal (prefrontal) bone present. Dermocranial fenestra absent in skull roof. Cleithrum narrow and elongate with just two limbs, the dorsal limb being far narrower than the ventral limb. Large, semicircular preoperculum with small exposed dermohyomandibular. Comparatively large operculum broad and club-shaped. Notochord completely surrounded by arcocentra. Ten to 15 dorsal ridge scales with three to six backward-pointing spines. Ventral ridge scales consist of 11 precloacal scales, with two backward curved spines and a single postcloacal scale. Cloaca is roofed by two comma-shaped scales. Four spines present on the postcloacal ventral ridge scale, with the first three being strongly curved and forward pointing and the most posterior spine straight and backward pointing in a posteroventral angle. Complete scales restricted to abdominal region, scale bars on rest of body.

Type Locality and Horizon—Haqel, northern Lebanon; Sannine Formation, early late Cenomanian, Upper Cretaceous.

Etymology— Latin for ‘rhomboid’ in allusion to the diamond-like body shape of the new species.

CONCLUSIONS: 

Flagellipinna rhomboides, gen. et sp. nov., is a recent addition to the high biodiversity of the exceptional pycnodont fauna of the Cenomanian Lebanese fossil beds (Appendix 1). Anatomical characters such as the presence of a postparietal process indicate that this taxon is a pycnodontid, which are well represented in the Cenomanian of Lebanon (Appendix 1).

The characteristics distinguishing Flagellipinna, gen. nov., from other pycnodonts is its acute anterior profile with a diamond-shaped body; a reduced operculum, which is nevertheless broader than typical pycnodont opercula and lies posterior to the dermohyomandibular and the preoperculum; a narrow and elongate cleithrum with two limbs; a posteroventral spine of the postcloacal scale, which is straight and backward pointing alongside three forward-pointing spines; a dorsoventrally flattened skull with a prognathous snout; a deep insertion of the dorsal and anal pterygiophores; and whip-like extended dorsal fin rays reminiscent of modern coral reef fishes such as Zanclus cornutus.

A combination of inferences from the specimens, the paleoenvironment of Haqel, and the invertebrate fauna that were found alongside Flagellipinna, gen. nov., suggests that it possibly inhabited reef slopes and fed from crevices on elusive armored prey such as bivalves, echinoderms, and gastropods. The interpretation of the smallest specimen of Flagellipinna, gen. nov., being a juvenile raises interesting questions regarding ontogeny and change in ecology during growth of this fish. The juvenile has an even deeper body shape than the adult along with a shift in skull position and shape, indicating that it was a more typical durophagous pycnodont that lived in shallower reef habitats and may have moved into deeper waters to feed from the crevices of the reef edge as it became older. Of course, more specimens of Flagellipinna, gen. nov., are necessary in order to confirm the validity of these morphological changes throughout its ontogeny, but this interpretation is supported by similar ontogenetic changes observed in modern taxa.

The Lebanese Cenomanian pycnodont fauna contains some of the most diversified assemblages of non-teleost actinopterygians in the Cretaceous. Such a diverse range of forms must have had a wide range of ecological requirements and life histories. Flagellipinna rhomboides, gen. et sp. nov., is not only another new species from this extraordinary assemblage, but the specimens described here also hint at how these fishes could have filled a particular niche in the Haqel ichthyofauna and how that niche may have changed during its life span.

John Joseph Cawley and Jürgen Kriwet. 2019. A New Genus and Species of Pycnodontid Fish Flagellipinna rhomboides, gen. et sp. nov. (Neopterygii, Pycnodontiformes), from the Upper Cretaceous (Cenomanian) of Lebanon, with Notes on Juvenile Form and Ecology. Journal of Vertebrate Paleontology.  DOI: 10.1080/02724634.2019.1614012   

twitter.com/Synapsida/status/1138105763241455616