A new giant titanosaur sheds light on body mass evolution among sauropod dinosaurs

CARBALLIDO, JOSÉ L.; POL, DIEGO; OTERO, ALEJANDRO; CERDA, IGNACIO A.; SALGADO, LEONARDO; GARRIDO, ALBERTO C.; RAMEZANI, JAHANDAR; CÚNEO, NÉSTOR R.; KRAUSE, JAVIER M.

PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON. SERIES B: BIOLOGICAL SCIENCES.

ROYAL SOC

Año: 2017 vol. 284

0962-8452

Titanosauria was the most diverse and successful lineage of sauropod dinosaurs.This clade had its major radiation during the middle Early Cretaceousand survived up to the end of that period. Among sauropods, this lineagehas the most disparate values of body mass, including the smallest andlargest sauropods known. Although recent findings have improved ourknowledge on giant titanosaur anatomy, there are still many unknown aspectsabout their evolution, especially for the most gigantic forms and the evolutionof body mass in this clade. Here we describe a new giant titanosaur, whichrepresents the largest species described so far and one of the most completetitanosaurs. Its inclusion in an extended phylogenetic analysis and the optimizationof body mass reveals the presence of an endemic clade of gianttitanosaurs inhabited Patagonia between the Albian and the Santonian. Thisclade includes most of the giant species of titanosaurs and represents themajor increase in body mass in the history of Titanosauria.