Osteology of Andescynodon (Cynodontia: Traversodontidae) from the Middle Triassic of Argentina

摘要

All available specimens of Andescynodon mendozensis and Rusconiodon mignonei are examined and restudied, and the latter species is regarded as a junior synonym of the former. The postcranial skeleton of this species is described for the first time; it generally shows primitive features of traversodontids. Andescynodon mendozensis is a small- to medium-sized traversodontid characterized by 9～11 upper postcanines in adults (fewer in larger individuals), the transverse ridge of upper postcanines lying anteriorly on the tooth, paracanine fossa penetrating the skull roof in adu it is differentiated from Pascualgnathus by relatively flatten skull, shorter and narrower temporal region, presence of four rather than three upper incisors.