Teyumbaita sulcognathus: A Triassic Rhynchosaur With a GREAT Sense of Smell

Paleoneurology of Teyumbaita sulcognathus (Diapsida: Archosauromorpha) and the sense of smell in rhynchosaurs

Authors:

Sales et al

Abstract:

Rhynchosaurs were a group of archosauromorphs that dominated the guild of herbivores during the early Late Triassic. Despite the large number of specimens available, paleobiological studies are rare in the literature, especially concerning the South American species. The present study analyzes the paleoneurology of Teyumbaita sulcognathus, a Brazilian hyperodapedontine rhynchosaur, along with its nasal cavity, based on tomographic images of the specimen UFRGS-PV-0232-T. Although the endocast only reveals the morphology of the posterior half of the encephalon due to the incompletely ossified braincase, it is possible to infer the presence of great olfactory bulbs because of their impressions left on the ventral surface of the frontals. Although the snout is relatively short, the areas of the nasal cavity probably devoted to olfaction were also large and, along with the size of the olfactory bulbs, it is possible to infer that olfaction was important for the behavior and ecology of T. sulcognathus, as previously proposed for Hyperodapedon.