THE BRAINCASE OF THE THEROPOD DINOSAUR MURUSRAPTOR: OSTEOLOGY, NEUROANATOMY AND COMMENTS ON THE PALEOBIOLOGICAL IMPLICATIONS OF CERTAIN ENDOCRANIAL FEATURES

PAULINA CARABAJAL, ARIANA; CURRIE, P.J.

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2017

0002-7014

A detailed description of theneuroanatomy of Murusraptor barrosaensis ?a mid-sized non-maniraptoran theropod from the Late Cretaceousof north Patagonia ? is based on the exceptionally preserved type braincase. CTscans provide new information on the braincase, brain, cranial nerves,encephalic vasculature, and inner ear of this taxon. Worldwide, relatively few non-maniraptorantheropod braincases have been described in detail and the new informationreported here is important to better understand the variability of braincasecharacters within the clade. This study suggests that megaraptorids have aparticular brain pattern that is different from those of other non-coelurosaur theropods,such as allosauroids and ceratosaurs, and different from that of some coelurosaurs,such as tyrannosaurids, although sharing more similarities with the latter. TheReptile Encephalization Quotient (REQ) of Murusraptoris within a range between those of Allosaurusand Tyrannosaurus; the OlfactoryRatio (OR) is, however, smaller than the observed in tyrannosaurids and allosauroids.The paleobiological implications on gaze stabilization, hearing, and olfaction inthe Argentinean taxon are still poorly understand.