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

BARRIOS, FRANCISCO; PREVITERA, ELENA; FILIPPI, LEONARDO S.; PAULINA-CARABAJAL, ARIANA; PIPO, LAURA; CRUZADO-CABALLERO, PENÉLOPE; MÉNDEZ, ARIEL H. ; GARRIDO, ALBERTO C.

Valencia

Congreso; 2nd Palaeontological Virtual Congress; 2020

Universidad de Valencia

The Ornithopoda clade has been traditionally poorly known in the fossil record of the UpperCretaceous in Argentina. In recent years, the continental sediments outcropping near the Rincónde los Sauces (Neuquén Province, Argentina) have showed a rich record with numerous remainsof indeterminate ornithopod, as well as the description of a new specie, Mahuidacursor lipanglef. Arecent field work carried out in the outcrops of Bajo de la Carpa Formation (Santonian, UpperCretaceous), in the area of La Invernada-Cerro Overo, has been fruitful in the discovery of postcranial ornithopod remains from two new sites. The remains present at least two ontogeneticstages, corresponding to an adult and a subadult specimens. Adult individuals would have amedium-size (6 m), similar to other ornithopod remains found in the same area. Almost all postcranial bones collected are poorly diagnosed, 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 similar to Macrogryphosaurusthan Talenkauen, with a rectangular and robust blade and a slender pubic peduncle.Unfortunately, the pelvic girdle of Mahuidacursor is not preserved, preventing further comparison.However, the assignation to this species cannot be discarded. These new fossils increase theknowledge of the Santonian ornithopod fauna from Rincón de los Sauces.