CARBALLIDO Jose Luis
The osteology of Chubutisaurus insignis del Corro, 1975 (Dinosauria, Neosauropoda) from the Middle Cretaceous of central Patagonia, Argentina
CARBALLIDO, JOSÉ LUIS; POL, DIEGO; CERDA, IGNACIO; SALGADO, LEONARDO
JOURNAL OF VERTEBRATE PALEONTOLOGY
SOC VERTEBRATE PALEONTOLOGY
Año: 2011 vol. 31 p. 93 - 110
Titanosauriform sauropods were one of the most widely distributed groups of dinosaurs during the Cretaceous. In contrast to most derived forms from the Upper Cretaceous, the most basal taxa of the group are poorly known. Thus, studies on these forms are of special interest for understanding the origin and early evolution of Titanosauria. Chubutisaurus insignis del Corro, 1975 is known from postcranial remains found in the Bayo Overo Member of the Cerro Barcino Formation (Chubut Group), which is commonly regarded as AptianCenomanian in age. Phylogenetic analyses that include Chubutisaurus recovered this taxon as the sister group to Titanosauria. Nevertheless, most published studies have not included this taxon, probably due to its brief description and fragmentary remains. Fieldwork conducted in the quarry where the holotype was found yielded new materials that are regarded as part of the same specimen. These new materials, together with additional undescribed, and briefly described elements, originally collected by G. del Corro, are described here. The new information allows the recognition of a more extensive diagnosis of this taxon. The phylogenetic analysis presented here resolves Chubutisaurus as the most basal somphospondylian.