Preliminary revision of the Cingulata Dasypodidae and Peltephilidae from the classical site Arroyo Chasicó (late Miocene), Buenos Aires Province, Argentina

BARASOAIN, DANIEL; MONTALVO, CLAUDIA; ZURITA, ALFREDO; TOMASSINI, RODRIGO

Puerto Madryn (Chubut)

Encuentro; Reunión de Comunicaciones de la Asociación Paleontológica Argentina; 2018

CENPAT-CONICET

The classical fossiliferous site Arroyo Chasicó constitutes the type locality of the Chasicoan Stage/Age (Late Miocene), a key period for understanding the evolutionary history of many mammal clades, including the Cingulata, because at that time there was an important faunistic replacement with the appearance of new taxa. It includes the most ancient fauna of the Pampean Region. In this context, a taxonomic review with modern criteria has been done for the Chasicoan cingulates. A preliminary revision of Dasypodidae and Peltephilidae was carried out based on new collections with precise geographic and stratigraphic data recovered from deposits of the Arroyo Chasicó Formation, outcropping in the site. The analysis allowed us to confirm the presence of the Eutatini Chasicotatus ameghinoi Scillato-Yané, the Euphractini Vetelia perforata Scillato-Yané, and the Peltephilidae Epipeltephilus kantii González-Ruiz. We added the first record of the Euphractini Proeuphractus limpidus Ameghino, Chorobates Reig, and Macrochorobates Scillato-Yané. Also, three different morphotypes (two Euphractini gen. et sp. indet. and one Eutatini gen. et sp. indet.) were identified; preliminary observations of their anatomical characters suggest that they could represent new taxa. Our results highlight that the Chasicoan was a period of high diversity for Dasypodidae, with a well representation of the tribes Euphractini and Eutatini. This fauna shows clear similarities with other Late Miocene (Chasicoan and Huayquerian) assemblages recovered from levels of the Cerro Azul Formation, outcropping in La Pampa and Buenos Aires provinces.