PALEONEUROLOGY OF CARNOTAURUSSASTREI (THEROPODA, ABELISAURIDAE): A PRELIMINARY STUDY BASED ON CT SCANS

CERRONI, M.A.; PAULINA-CARABAJAL, ARIANA; NOVAS, F.E.

Congreso; Jornadas Argentinas de Paleontología de Vertebrados; 2017

The endocranial morphology of abelisaurids is only known for Aucasaurus garridoi Coria, Chiappe and Dingus, and Viavenatorexxoni Filippi, Méndez, Juárez Valieri and Garrido from Argentina, Majungasaurus crennatissimus Depéret from Madagascar, anda partial endocast of Indosaurus matleyi Huene and Matley from India. Here, we present the complete cranial endocast ofCarnotaurussastrei Bonaparte (MACN-CH 894) based on CT scans. Although the most delicate structures of the endocranialcavity are not clearly observed in the data set, the general morphology of the brain, plus some cranial nerves (i.e., CNs II, V,VI and XII) and some blood vessels (i.e., caudal middle cerebral brain and sphenoidal artery) are recognized. The shape andproportions of the endocranial cavity resemble those present in other Cretaceous abelisaurids, including well-marked cerebralhemispheres, robust and elongate olfactory tract and elongate, and slightly divergent olfactory bulbs. However, the olfactorytracts and bulbs of Carnotaurus are curved ventrally (therefore being aligned with the cerebral hemispheres), unlikethe horizontally oriented structures described for other abelisaurids so far. Carnotaurus shares with the South Americanforms the presence of a low dorsal expansion (or pyramidal peak) and the angle between midbrain and hindbrain. Furtherstudies will be focused on the particular olfactory region of the brain of Carnotaurus, which may respond to a sensorial capabilitydifferent from that developed in Aucasaurus, Viavenator and probably Abelisaurus Bonaparte and Novas.