Rincón de los Sauces as a hot spot of ornithopod remains from the Upper Cretaceous

CRUZADO-CABALLERO, PENÉLOPE; FILIPPI, LEONARDO S.; BARRIOS, FRANCISCO; MÉNDEZ, ARIEL H.; PAULINA-CARABAJAL, ARIANA; PREVITERA, MARÍA ELENA; GARRIDO, ALBERTO C.; GONZÁLEZ-DIONIS, JAVIER

Villa El Chocón

Jornada; III Jornadas de Paleontología de la Cuenca Neuquina; 2021

Museo Municipal ?Ernesto Bachmann?

Elasmaria was defined as a small endemic clade of Argentina formed by the Talenkauen and Macrogryphosaurus species. Since then, different phylogenies have been proposed including various Argentinian and Australian taxa. In Argentina, the fossil record of this clade is distributed between the provinces of Neuquén, Chubut and Santa Cruz. The first being the one with the largest record, largely due to the fact that in recent years the continental sediments of the Plottier and Bajo de la Carpa formations (Upper Cretaceous, late Coniacian?late Santonian and Santonian respectively). The fossils of numerous indeterminate ornithopod remains (probably elasmarians) and the elasmarian Mahuidacursor (MAU-Pv-CO-596) have been recollected in the area of ?Cerro Overo-La Invernada? near Rincón de Los Sauces locality (Neuquén Province, Argentina). The remains found are mainly postcranial (cervical, dorsal and caudal vertebra; coracoid; ilium, fragments of pubis, ischium and femora; and phalanges; MAU-Pv-PH-458, MAU-Pv-CO-564 to 565, 569 to 579 and 663; MAU-Pv-LE-616 to 618). These present different ontogenetic states (adult, subadult and juvenile), showing a possible gregarious behaviour for this group, which was widely distributed throughout the Rincón de los Sauces area. The average size of the remains indicates that the adult individuals would have a medium size (6 m), similar to the estimated size for Macrogryphosaurus and Talenkauen. Each new fossil remains of this clade that we find improves our ornithopod distribution map in Argentina and complements the knowledge of the paleobiodiversity of the Santonian vertebrate fauna.