MORFOLOGIA DENTARIA y BIOMECANICA MASTICATORIA DE LOS CINODONTES (REPTILIA, THERAPSIDA) DEL TRIASICO ARGENTINO: ll. EXAERETODON FRENGUELLI CABRERA (TRAVERSODONTIDAE)

Abstract

Finely preserved remains ofupperpostcanines of Exaeretodon frenguelll Cabrera (Reptilia, Therapsida, Traversodontidae) allowedto recognize several dental specializations and to infer the masticatory mechanics and feeding habits of these late Triassic, hervibore South American gomphodont cynodonts. Inferred chewing mechanisms suggest an extensive oral treatment of massive - rather than foliar- vegetal structures, favouring a high energetic profit from food. Interproximal relationships between upper postcanines suggest a complex embedding system of these teeth, acting as guides of each other during ontogeny, thus working as a compact dental battery. These cynodonts were monophyodont and had browser-like habits; their feeding strategy most probably depended on the seasonal availability of resources in their relatively damp and warm habitats. Diet of these cynodonts may have consisted of roots and rhizomes, stems and strobiles of Equisctales, seeds of Coniferales and Cycadales, and reproductive structures of Ginkgoales and PtEridospermales.