NEW TURTLE REMAINS FROM PLOTTIER FORMATION NEAR RINCÓN DE LOS SAUCES (NEUQUÉN, ARGENTINA): DO CEARACHELYINI EXTENDS IT BIOCRON IN GONDWANA?

MANIEL IGNACIO JORGE; DE LA FUENTE MARCELO SAUL; FILIPPI LEONARDO

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

The new turtle remains came out from Plottier Formation (Coniacian?Santonian) exposed in thePuesto Hernández production field. The site is located 25 km to the northwest of the city of Rincón de Los Sauces, in the north of the province of Neuquen, Patagonia, Argentina. These remains (MAU-PVPH 418) consist in a carapace, essentially preserved by impressions, and an articulated pelvic girdle. The new specimen is referred to as a Pleurodira by its pelvic girdle connected by suture to the carapace. The contour observed in the midline of the carapace (neural series) shows a 6-sided first neural with short posterolateral margins, a second neural bone 4-sided shaped, and a complete neural series of seven neurals extended at least until the eighth costals, with the last one being heptagonal in shape. Indeed, this new specimen shows this peculiar neural pattern as Elkanemys pritchardi (Bothremydidae, Cearachelyini) from Candeleros Formation, Cearachelys placidoi (from Santana Formation, Brazil), and Galianemys spp. (from Kem Kem beds, Morocco). Up to now, the Gondwanan record of Cearachelyini ranges from the Aptian to Cenomanian. MAU-PV-PH 418 is referred to as cf. Elkanemys extending the biocron of Cearachelyini not only in Patagonia but also in Gondwana. The presence of new Pelomedusoides remains in Plottier Formation also fill the gap of this clade between Portezueloemys patagonica (Portezuelo Formation) and MPCA 7049 (Anacleto Formation) in the Neuquén Basin