Neuroanatomy of Titanosaurid Dinosaurs From the Upper Cretaceous of Patagonia, With Comments on Endocranial Variability Within Sauropoda

摘要: The purpose of this study is to provide a detailed description the neuroanatomy Bonatitan, Antarctosaurus, and an unnamed titanosaur from Rio Negro, Argentina including first observations on inner ear two taxa using CT scans. materials were compared with previously described sauropod endocasts other less complete braincases Argentina. cranial show general morphology sauropods being bulbous, anteroposteriorly short transversely wide, enlarged posteroventrally pro- jected pituitary body. Particular traits are extremely horizontal olfactory tract, absence floccular process single root for nerve XII. In addition, in basicranium abducens (CN VI) does not penetrates fossa internal carotid artery enters medial aspect basipterygoid cess, resulting external opening vessel that visible lateral view braincase. titanosaurid also exhibits par- ticular traits, such as robust semicircular canals, anterior poste- rior canals subequal size. variation observed endocranium indicates evolutionary tendency tita- nosaurs toward anteroposterior shortening midbrain, reduction size ear, particular canal. This, together lack suggests narrower range movements head clade. Anat Rec, 295:2141-2156, 2012. V C 2012 Wiley Periodicals, Inc.