Dental and craniomandibular anatomy of Peligrotherium tropicalis: The evolutionary radiation of South American dryolestoid mammals.

摘要

Peligrotherium tropicalis is a highly derived dryolestoid from the Hansen Member of the Paleocene Salamanca Formation in Patagonia, Argentina. Herein, the first skull for the species is described. Prior to finding the specimens discussed here, members of this group have only been known by teeth and fragments of dentaries. Now, with the exception of the incisors, all other dental elements of Peligrotherium are now known. The skull and jaws of Peligrotherium are massively built and are distinct from those of non-South American dryolestoids, yet reminiscent of those of mesungulatids. The gross dental morphology corresponds closely to that of other Southern dryolestoids, mesungulatids in particular. With this new information, Peligrotheriidae is redescribed and a new clade that is here given the suprafamiliar; Mesungulatomorpha, is erected to include Peligrotheriidae along with two other closely related South American dryolestoids; Reigitheriidae and Mesungulatidae.