INVESTIGADORES
OTERO Alejandro
congresos y reuniones científicas
Título:
A large titanosaur sauropod from the Early Cretaceous of Patagonia, Argentina
Autor/es:
JOSE CARBALLIDO; ALEJANDRO OTERO; IGNACIO CERDA; LEONARDO SALGADO; DIEGO POL
Lugar:
Ituiutaba
Reunión:
Simposio; 1º Brazilian Dinosaur Symposium; 2013
Institución organizadora:
Universidade de Uberlandia
Resumen:
Gigantic body size evolved independently in different sauropod lineages, being the Late Cretaceous Patagonian titanosaurs the clade in which the largest dinosaurs are registered (Argentinosaurus and Puertasaurus). Nevertheless the incompleteness of these giant taxa obscures the characterization of their relationships among basal titanosaurs and therefore precludes the fully understanding of the evolution of extreme gigantism within this clade. We present a giant and well-preserved titanosaur specimen, recently discovered in a new locality of the Cerro Barcino Formation (Early Cretaceous; northern Patagonia), which represents the first definitive record of this group in the Early Cretaceous of Patagonia. The already exposed remains are semi-articulated and include: a femur, both pubes, both ischia, one possible ilium, a scapula, a humerus, dorsal and caudal vertebrae, ribs, one chevron, and an isolated tooth. Additionally, several not excavated bones were observed, which represents more axial and limb materials, indicating that this specimen could be considered the most complete giant titanosaur. Field observations allow a preliminary taxonomic characterization of the specimen, which can be recognized as a titanosauriform due to the presence of slender tooth (SI= 3.5), spongy presacral bony texture, dorsal ribs with pneumatic cavities, and femur with lateral bulge and anteroposteriorly compressed shaft. Its inclusion among titanosaurs is supported by procoelus anterior to posterior caudal vertebrae. Nevertheless, the recognition of a D-shaped tooth, with v-shaped wear facet indicates a basal position among this clade. The importance of this new specimen relies on its completeness and well preservation that contrast with the average record of gigantic titanosaurs worldwide. Besides, whereas the already known taxa comes from Late Cretaceous, our new specimen is registered in the Early Cretaceous, demonstrating that extreme large body titanosaurs evolved before that previously thought.