NEW SAURIAN EVIDENCE FROM CANDELEROS FORMATION (CENOMANIAN; UPPER CRETACEOUS) OF SOUTHERN NEUQUÉN BASIN (EL SAUCE, PATAGONIA, ARGENTINA)

BELLARDINI, FLAVIO; BAIANO, MATTIA A.; MANIEL, IGNACIO; GARRIDO, ALBERTO C.; WINDHOLZ, GUILLERMO J.; PINO, DIEGO A; MESO, J.; CIAFFI, A.; CORI, R.

Salta

Jornada; Reunion de Comunicaciones de la Asociacion Paleontologica Argentina; 2022

APA IBIGEO IEBI UNSA IBIGEOP

The fluvial deposits of the Candeleros Formation widely outcrop in the Neuquén Basin, preservingan abundant and diversified saurian fauna of the “Middle” Cretaceous of northern Patagonia. Thefossil record of the Candeleros Formation counts with many fossiliferous sites in Rio Negro andNeuquén Provinces; however, most of them come from the upper section of the unit. In thiscontribution, we report several saurian evidence from a new fossiliferous locality of El Sauce (PicúnLeufú, Neuquén Province), where the lower section of the Candeleros Formation outcrops. Recentfieldworks allowed the finding of: several axial and appendicular sauropod remains, an almostcomplete femur that tentatively refers to an indeterminate, large-sized theropod dinosaur, someisolated plastron elements of indeterminate turtles, and isolated sauropod, pterosaur, and tridactyldinosaur footprints. The sauropod specimens come from different sites on one laterally extended,fossiliferous level composed by grey, fine sandstones and green to purple mudstones, whereas thetheropod femur and the footprints were found on brown coarse sandstones, all of which outcrop atthe base of the Candeleros Formations. The diversified faunal composition recorded in the newlocality of El Sauce is concordant with the slightly older Lohan Cura Formation, suggesting thepersistence of specific paleoenvironmental conditions on the southern Neuquén Basin, at leastduring the Early-Late Cretaceous transition. Furthermore, this new evidence shows part of thefaunal components of Lohancuran tetrapod assemblage, allowing new morphological andtaxonomical comparisons with the saurian fauna of the upper section of Candeleros Formation. Newdata from the Lohan Cura and Candeleros formations will improve the knowledge about thediversification and the paleobiogeographical evolution of the saurian fauna during the Cretaceous ofNeuquén Basin.