Species New to Science

We infer the neonatal metabolic rate at rest (RMR) and at maximum activity levels (MMR) of the hadrosaurid dinosaur Maiasaura peeblesorum from the Two Medicine Formation of Montana (USA) using Phylogenetic Eigenvector Maps applied to the following osteohistological features: the Relative Primary Osteon Area and the size of the femoral nutrient foramen as proxies. We investigate the locomotor/motor activity of the neonates by comparing the difference between maximum and minimum rates of oxygen consumption—referred to as aerobic scope and denoted as ΔMR, as a proxy of their activity levels. Applied to Maiasaura, this novel methodology allows for a quantitative assessment of its neonatal state and to deduce its dependence on parental care. The inferred neonatal RMR values for Maiasaura are similar to those of present-day fast-growing endotherms. As for the aerobic scope, M. peeblesorum neonates have a ΔMR value similar to those observed in present-day altricial birds that need intensive parental care. This result is consistent with the previously proposed hypothesis of nidicolous M. peeblesorum requiring parental care. Finally, based on age-estimations from M. peeblesorum neonate remains found both in and outside nest sites, we estimate that this species remained in the nest for approximately 40–75 days. Maiasaura provides a useful ecological baseline from which to infer neonatal states in an other hadrosaur of similar adult size—Hypacrosaurus stebingeri, whose differing ecological traits point to a relatively more precocial condition. The diversity of post-hatching reproductive strategy partly explains the adaptation of hadrosaurs to a wide range of paleolatitudes and environments.

Hugo Bert, Holly Woodward, Nicolas Rinder, Romain Amiot, John R. Horner, Christophe Lécuyer, Mariana Sena and Jorge Cubo. 2025. Neonatal State and Degree of Necessity for Parental Care in Maiasaura based on inferred Neonatal Metabolic Rates. Scientific Reports. 15: 24827. DOI: doi.org/10.1038/s41598-025-06282-5 [10 July 2025]

In 2015, a partial skeleton of the Late Triassic dinosaur Plateosaurus trossingensis was excavated from Frick, Switzerland, and subsequently mounted at the Natural History Museum of Vienna in 2021. This specimen includes an almost complete series of tail vertebrae, with a well-preserved, articulated whip-like distal end. The preserved tail structure provides valuable insights into the morphological implications of tail function and its potential role in the behaviour of Plateosaurus. Using the caudal vertebrae, we reconstructed and analysed the potential tail-lashing capabilities of Plateosaurus, comparing its biomechanics with those of other fossil and extant long-tailed reptilian taxa, including the extinct sauropod Diplodocus, the extant Asian water monitor (Varanus salvator), and the green iguana (Iguana iguana). Our results indicate that the tail of P. trossingensis was highly flexible, with an estimated kinetic energy output ranging between 0.537 and 1.616 kJ during rapid strikes, comparable to the defensive tail use observed in modern reptiles. These findings suggest that tail-whipping may have played a role in predator deterrence and intraspecific interactions in Plateosaurus.

Thomas Filek, Matthias Kranner, Ben Pabst and Ursula B. Göhlich. 2025. Tail of Defence: An Almost complete Tail Skeleton of Plateosaurus (Sauropodomorpha, Late Triassic) reveals possible Defence Strategies. Royal Society Open Science. DOI: doi.org/10.1098/rsos.250325 [21 May 2025]

 

Otters, subfamily Lutrinae (Mustelidae), are predators that thrive in aquatic environments, and have a semiaquatic to fully aquatic lifestyle. While modern otters are found across the globe, their fossil history is limited, primarily documented by fragmented dentognathic remains. In this work, we report on and describe new dental remains of a medium-sized Lutrinae from the Late Miocene of Baccinello and Casteani (Tuscany), improving the poor fossil record of the subfamily in Europe. Tyrrhenolutra helbingi Hürzeler, 1987 is a poorly known species, described on some dental remains from the Baccinello mines and a few other localities. Considering its peculiar morphology, it has often been overlooked in the scientific literature. Description of the material stored at the Naturhistorisches Museum, Basel and Museo di Geologia e Paleontologia dell’Università di Firenze offers new insights on the intraspecific variability and dental morphology of this taxon. The comparative study of these findings highlights several morphological and biometrical similarities between T. helbingi and Paludolutra maremmana Hürzeler, 1987, which allow us to redefine these taxa as Tyrrhenolutra maremmana nov. comb. We carried out a total-evidence cladistic analysis seeking support for morphometric and morphological similarities between T. “helbingi” and “P.” maremmana. The resulting parsimony analyses support the synonymy, excluding a close relationship of T. maremmana with Paludolutra of Italy and Spain, as previously thought. Furthermore, we confirm a long-forgotten hypothesis identifying Limnonyx Crusafont Pairó, 1950 as the possible continental ancestor of Tyrrhenolutra.

Keywords: Neogene; Baccinello; Carnivora; mustelid; taxonomy; cladistic.

Venom is a metabolically expensive secretion used sparingly in a variety of ecological contexts, most notably predation and defence. Accordingly, few animals employ their toxins from a distance, and venom-squirting behaviour is only known from select taxa. In scorpions, species belonging to two genera are known to spray venom when threatened, and previous work in Parabuthus transvaalicus shows that venom delivery depends on perceived levels of threat. Here, I describe Tityus (Tityus) achilles sp. nov., a new species of buthid scorpion from Cundinamarca, Colombia. Remarkably, this species is capable of venom spraying, a first for both the genus and the South American continent. Using frame-by-frame video analysis and ballistic equations, I show that T. (Tityus) achilles sp. nov. employs not one, but two types of airborne defences with dramatic differences in reach and venom expenditure. Further, the new species uses an unusually large reserve of prevenom-like secretion for spraying, as opposed to the costly venom used by other spraying scorpions. In light of these key specializations, I propose that toxungen spraying convergently evolved in response to different selection pressures, laying the groundwork for future investigation.

behaviour, Colombia, evolutionary biology, new species, taxonomy, toxin, toxungen, venom spitting

A new species of assassin bug, Gorareduvius gajarrangarnang sp. nov. is described from the Kimberley region, Western Australia, using digital images, scanning electron micrographs and X-ray microtomography. Natural history and prey capture by this species is described, revealing the use of sticky Triodia resin in prey capture. This is only the second documented instance of resin use by an Australian reduviid.

 

Similar to G. westraliensis, being mostly black in colouration, apterous, with an elongate and parallel-sided body, elongate limbs with swollen femoral apices, but distinguished by its somewhat smaller size, by the broad yellow to orange metafemoral annulation (vs yellow to orange profemoral annulation in G. westraliensis), the yellow to orange antennae (vs black with yellow apices) the more prominent and erect tubercles on the abdominal tergites, and by the structure of the male aedeagus.

Etymology: The specific epithet gajarrangarnang, derived from the Miriwoong language, spelled ‘gajarrangarnang’ meaning ‘spinifex dweller, ’ refers the grass (Triodia spp.) from which these assassin bugs extract resin. Miriwoong was once commonly spoken near the region where the type specimen was found, but is now a critically endangered language. This name alludes to both the fact that these assassin bugs are usually found associated with resinous species of Triodia, and that they cover themselves with resin from these plants. This name was suggested and approved by the Elders and language consultants who were contacted through the Mirima Dawang Woorlab-gerring Language and Culture Centre (https://mirima.org.au)

 

Anuran amphibians exhibit the greatest diversity of reproductive modes among tetrapod vertebrates. The Andamanese Charles Darwin's frog, Minervarya charlesdarwini, is the only species of the family Dicroglossidae that is known to naturally deposit eggs in water-filled cavities of tree holes or buttresses, where they then undergo exotrophic development. We describe the reproductive behavior in this species that involves a unique combination of traits: (1) Males produce complex advertisement calls comprising at least three different call types, in addition to a type of aggressive call. (2) Unpaired males exhibit agonistic interactions with each other and with mated pairs. (3) Mate selection, amplexus, and oviposition take place inside water-filled cavities. (4) During axillary amplexus, mating pairs synchronously switch between head-up and head-down positions above and below the water surface using both forward and backward movements. (5) At the time of egg laying, amplectant pairs are in an upside-down position on the cavity walls with their bodies completely outside the water. (6) Eggs are deposited over multiple bouts on the inner walls of the cavities and terrestrially above the water surface. Upside-down spawning in M. charlesdarwini is a unique trait among phytotelm-breeding terrestrial frogs. The combination of terrestrial oviposition sites in water-filled phytotelmata and the upside-down egg-laying posture is a novel report for the family Dicroglossidae and perhaps all anurans. This specialized behavior is also likely derived for a species that is embedded in a group of largely aquatic-breeding minervaryan frogs. Although M. charlesdarwini appears to be an obligate phytotelm breeder, individuals were often observed breeding inside cylindrical, water-filled plastic sapling bags in plant nurseries adjacent to fragmented forest patches, or in rain-filled discarded plastic, glass, or metal containers left as trash at the forest edge. Use of such unnatural breeding sites is likely a forced behavioral shift in response to rapidly changing forest landscapes associated with recent habitat loss and fragmentation. Our findings call for conservation attention to this habitat specialist, which, although locally abundant, is an endemic and threatened species of the Andaman Islands.