New rebbachisaurid cranial remains (Sauropoda, Diplodocoidea) from the Cretaceous of Patagonia, Argentina, and the first endocranial description for a South American representative of the clade

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

JOURNAL OF VERTEBRATE PALEONTOLOGY

SOC VERTEBRATE PALEONTOLOGY

Lugar: Lawrence; Año: 2016

0272-4634

Here we report newrebbachisaurid material (MMCh-PV 71) recovered from the Candeleros Formation (Cenomanian)of northwest Patagonia, Argentina. The cranial remains consist of a partialbraincase and a right quadrate. Fractures in the braincase exposed theendocranial cavity allowing the first study of the brain and inner earmorphologies for a South American rebbachisaurid. The braincase and cranialendocast both exhibit traits similar to those observed in the Cretaceousrebbachisaurs Nigersaurus from Africaand Limaysaurus from Argentina, althoughin terms of osteology the South American taxa are highly similar. The endocastof MMCh-PV 71 is more similar to that of Nigersaurusthan to Diplodocus and Camarasaurus, suggesting some probablerebbachisaurid features such as the noteworthy presence of the flocculus. The overallmorphology of the quadrate shows similarities with Limaysaurus and Nigersaurus.However, differences such as the broader posterior fossa and the shape andorientation of the head and the pterygoid process indicate that the new specimencould represent a distinct taxon.