Cranial endocast of the carcharodontosaurid theropod Giganotosaurus carolinii Coria and Salgado.

PAULINA CARABAJAL, A.; CANALE, J.I.

Trelew, Chubut

Jornada; XXIII Jornadas Argentinas de Paleontología de Vertebrados.; 2007

Museo E. Feruglio

A complete latex endocast was made after removing the sediment filling the brain cavity of the braincase of Giganotosaurus, thereby allowing the description of the endocranial anatomy of the specimen. The endocast is compared with the few other known natural or artificial theropod endocasts. As in Carcharodontosaurus saharicus Stromer, the olfactory bulbs are aligned with the forebrain, the midbrain is posteroventrally inclined and the hindbrain is parallel but ventral to the forebrain, showing similarly angled cephalic and pontine flexures. The olfactory bulbs are well developed and are separated by a bony septum. The olfactory tract is robust, long and shallowly upward convex, and is vascularized by two pairs of unrecognized blood vessels. The floccular process of the cerebellum is large and is dorsal to nerve V. The cranial nerves and blood vessels have a similar disposition as in Carcharodontosaurus with the difference that in Giganotosaurus there is only one branch for cranial nerve XII and cranial nerve XI has a separated internal opening from the Vagus foramen (metotic foramen). In Carcharodontosaurus is a separate opening as well, but it is anterior in position and was probably for cranial nerve IX. The length of the endocast, including the olfactory bulbs, is approximately 19% longer than the endocast in Carcharodontosaurus.