A new representative of the Hypertraguloidea (Tragulina, Ruminantia) from the Khoer-Dzan locality in Mongolia, with remarks on the relationships of the Hypertragulidae. American Museum novitates ; no. 3225

24 p. : ill. ; 26 cm.Includes bibliographical references (p. 21-24)."A new hypertraguloid, Praetragulus electus, n. gen. and sp., is described from part of a skull and numerous mandibles, teeth, and limb bones from the Lower Oligocene of the Khoer-Dzan locality in eastern Mongolia. Besides species from Khoer-Dzan, Lophiomeryx gobiae from Ardyn-Obo is referred to Praetragulus. Praetragulus possessed a mixture of primitive and derived features that give evidence of its early offshoot from the Tragulina, connected with the Asian early adaptive radiation of that group. The peculiarities of the skull structure and the short premolar row, together with unfused magnum and trapezoid as well as unfused central metapodials, lead to the assumption of a close relationship between the Central Asian and the North American hypertragulids. The ancestor of the latter group may have invaded North America during the Eurasian-American faunal exchange in the late Middle Eocene, approximately 41 Ma"--P. [1]

A new elasmosaurid plesiosaur from the lower Cretaceous of Queensland, Australia

A nearly complete but badly crushed elasmosaurid plesiosaur skull is described from the Upper Albian Toolebuc Formation of northern Queensland, Australia. The specimen has a long history, being previously referred to the Australian Aptian genus ‘Woolungasaurus’ (considered a nomen dubium), as well as provisionally to Elasmosauridae gen. et sp. nov., and most recently to Tuarangisaurus (Campanian-Maastrichtian, New Zealand and potentially Patagonia). The present assessment alternatively proposes assignment to a new taxon, Eromangasaurus carinognathus, gen. et sp. nov., uniquely characterized by the presence of seven premaxillary teeth (three lateral pairs, one midline), an elongate mandibular symphysis with prominent ventral midline keel, and a combination of osteological features variably developed in other elasmosaurids. Cladistic analysis using 43 discrete cranio-dental and vertebral characters coded for 16 ingroup and one outgroup taxon supports this conclusion, indicating that E. carinognathus is a crown-group elasmosaurid of more derived grade than Occitanosaurus (Lower Jurassic, Toarcian, France). Affinities with other Cretaceous elasmosaurids are poorly resolved. Nevertheless, a close relationship with Tuarangisaurus is not substantiated; instead, E. carinognathus forms a discrete clade with Terminonatator (Campanian, Canada)