A new giant titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous of Northwestern Patagonia, Argentina

Abstract

Chucarosaurus diripienda gen. et sp. nov. is a new and large titanosaurian sauropod from the Neuquén Basin, Rio Negro Province, Patagonia. The specimen was discovered in the Upper Cretaceous strata of the Huincul Formation (middle Cenomanian–lower Turonian). It includes appendicular and relatively slender elements, with a femoral total length of about 1.9 m long. This taxon shows a unique combination of characters indicating that appendicular bones such as the femur, ischium and tibia, show a remarkable morphological variety, greater than previously described, and are morphologically informative as source of phylogenetic data. A cladistic phylogenetic analysis placed Chucarosaurus well nested within the Colossosauria clade.