Patagosphenos watuku gen. & sp. nov.
Adriel R. Gentil, Federico L. Agnolin, Jordi A. Garcia MarsÃ, Matias J. Motta & Fernando E. Novas (2019)
Bridging the gap: sphenodont remains from the Turonian (Upper Cretaceous) of Patagonia. Palaeobiological inferences.
Cretaceous Research (advance online publication)
Rhynchocephalians are a lepidosaur clade with a single living species. Here we report the first record of an eilenodontine sphenodontian from Turonian beds in South America. The new Turonian basal eilenodontine sphenodontian, Patagosphenos watuku gen. et sp. nov, is described. The specimen is represented by partial cranial and postcranial remains, being very similar to other eilenodontines such as Kaikaifilusaurus and Eilenodon. Moreover, the genus Kaikaifilusaurus is reported for the first time from Turonian beds. Furthermore, this genus is revalidated, being previously considered as a nomen dubium. Paleohistological analysis of Patagosphenos gen. nov reveals a similar bone microstructure to that of the living Sphenodon. We infer that physiological adaptations to survive in cold (freezing conditions) environments may constitute the key pre-adaptation that allowed Sphenodon to survive the Cretaceous-Palaeogene boundary.
Piotr Bajdek, Tomasz Szczygielski, Agnieszka KapuÅciÅsk & Tomasz Sulej (2019)
Bromalites from a turtle-dominated fossil assemblage from the Triassic of Poland
Palaeogeography, Palaeoclimatology, Palaeoecology (advance online publication)
Highlights
Studied coprolites provide information on a turtle-dominated Late Triassic ecosystem.
Coprolites were produced by sharks, turtles, theropods, and a sizable herbivore.
Carnivores fed predominantly on fish in this fluvial environment.
The turtle Proterochersis porebensis was likely omnivorous and semiaquatic.
Life habits of early turtles were similar to those typical of extant taxa.
Abstract
Bromalites (coprolites and possibly some cololites) from a turtle-dominated fossil assemblage from the Upper Triassic of Poland were studied. Bromalites collected at the PorÄba site are grouped within four morphotypes (A, B, C, and D) attributable to sharks, medium-sized omnivorous or carnivorous tetrapods (likely turtles), sizable carnivorous archosaurs (likely theropods) and an indeterminate big herbivorous tetrapod (possibly dicynodonts or aetosaurs), respectively. Food residues, abundant eggs (possibly of parasites), and microorganisms were found within the materials. Several lines of evidence suggest that at least part of the type B specimens might have been produced by turtles, since (a) turtles are the prevailing tetrapods in the assemblage (over 4/5 of tetrapod bone remains), (b) coprolites are of adequate size, and (c) they appear to have been produced by a carnivore of a low metabolic rate, as seen in extant turtles. The content of the type B specimens would imply that the Late Triassic turtle Proterochersis porebensis was partly piscivorous, but possibly complemented its diet with a more diversified foodstuff, including plants. Semiaquatic habit of Proterochersis porebensis might also provide a taphonomic explanation of the relative abundance of turtle remains at the PorÄba site, Poland. Shark bromalites and coprolite specimens attributable likely to theropod dinosaurs also contain abundant fish remains. Origin and classification of spiral and scroll bromalites left by fish are discussed in addition.