The ornithopod dinosaurs from the Upper Cretaceous (Bajo de la Carpa Formation, Santonian) of Rincón de los Sauces (Neuquén Province, Argentina)

CRUZADO-CABALLERO, PENÉLOPE; FILIPPI, LEONARDO SEBASTIÁN; BARRIOS, FRANCISCO; MÉNDEZ, ARIEL HERNÁN; PAULINA CARABAJAL, ARIANA; PREVITERA, MARÍA ELENA; GARRIDO, ALBERTO CARLOS; PIPO, LAURA

Congreso; 2nd Palaeontological Virtual Congress; 2020

The Ornithopoda clade remains poorly known in the Late Cretaceous fossil record from Argentina. In recent years, continental sediments outcropping near the Rincón de los Sauces (Neuquén Province, Argentina) have yielded abundant material, with numerous remains of indeterminate ornithopods, as well as a new taxon, Mahuidacursor lipanglef. Recent fieldwork in the Bajo de la Carpa Formation (Santonian, Upper Cretaceous), in the area of ?La Invernada-Cerro Overo?, has led to the discovery of postcranial ornithopod materialfrom two new sites. The remains correspond to at least two ontogenetic stages, including anadult and a subadult specimens. Adult individuals would have a medium-size (6 m), similar to other ornithopod remains found in the same area. Almost all collected postcranial bones are poorly diagnostic, except for the ilium MAU-Pv-CO-663. It is a right almost complete ilium (the preacetabular is broken), with a length similar to that of Macrogryphosaurus. Also, MAU-Pv-CO-663 shows a profile more closely resembling Macrogryphosaurusthan Talenkauen, with a rectangular and robust blade and a slender pubic peduncle. Unfortunately, the pelvic girdle of Mahuidacursor is not preserved, preventing further comparisons so far. However, the assignation to this species cannot be discarded. These new fossils increase the knowledge of the Santonian ornithopod fauna from Rincón de los Sauces.