New records of Vetelia Ameghino (Mammalia, Xenarthra, Dasypodidae) in the Miocene of Argentina: anatomical and paleobiogeographic implications

GONZÁLEZ RUIZ, L.R; GÓIS, F.; SCILLATO-YANÉ, G.J.; OLIVA, C.; CONTRERAS, V.H; ESTEBAN, G.

Mendoza

Congreso; 4th International Paleontological Congress; 2014

CONICET-IPA

Vetelia Ameghino (Dasypodidae, Euphractini) includes three described species: 1) V. puncta Ameghino (early and middle Miocene; Santacrucian sensu lato, Friasian sensu stricto, Colloncuran); 2) V. perforata Scillato-Yané (middle and late Miocene; Mayoan, Chasicoan, Huayquerian, ?Araucanian?); and 3) V. gandhii Esteban and Nasif (late Miocene; Chasicoan, Huayquerian). The type specimens of all species, and most attributed specimens, are disarticulated osteoderms of the carapace. Since its original description in 1891, only one fragment of right dentary (associated with incomplete osteoderms) has been described in the genus (V. perforata, MLP 76-VI-12-95, ex-MLP CH 96, Arroyo Chasicó Formation, late Miocene, Chasicoan). Therefore, discoveries of skulls and mandibles associated with osteoderms became important. Here we present new specimens of Vetelia from Neogene outcrops of San Juan and Buenos Aires provinces: 1) Vetelia gandhii: PSJV 289 (Loma de Las Tapias Formation, late Miocene, Chasicoan, San Juan Province), which represents the most complete specimen of the genus and includes most part of the skull, a fragment of left dentary, and articulated fragments of the dorsal carapace; PSJV 290 (Loma de Las Tapias Formation, late Miocene, Chasicoan, San Juan Province), a fragment of skull and two associated osteoderms; 2) Vetelia sp.: MLP 64-VI-21-3 (Los Berros, late Miocene, San Juan Province), a fragment of right dentary; 3) Vetelia perforata:MMH-CH-87-7-109 (Arroyo Chasicó Formation, late Miocene, Chasicoan, Buenos Aires Province), almost complete right dentary and three associated osteoderms. After preliminary analyses of all specimens and other several isolated osteoderms as well, we identified new characters of Vetelia: 1) presence of at least five movable bands in the dorsal carapace; 2) presence of a rudimentary scapular buckler; and 3) presence of at least nine upper and lower molariforms. Vetelia perforata has a wider paleobiogeographic distribution than V. gandhii, with records in Neogene sediments of south, central and west Argentina (Santa Cruz, Chubut, Buenos Aires, La Pampa, San Juan, La Rioja and Catamarca provinces) whereas V. gandhii is restricted to the west (San Juan and Catamarca provinces). Finally, although both species are present during the late Miocene they have never been recorded together in the same fossil locality.