Un nuevo osteopigino (Chelonii: Cryptodira) de la Formación Roca (Paleoceno inferior) de Cerros Bayos, provincia de La Pampa, Argentina.

DE LA FUENTE, M.; CASADÍO, S.

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2000 vol. 37 p. 235 - 246

0002-7014

A new genus and species of osteopygine turtle, Pampaemys meridionalis n. g. n. sp. from the Roca Formation outcroping at Cerros Bayos (La Pampa province, Argentina) is described. The affinities of this new species with North American and European osteopygine turtles is discussed. The South American new taxon consists in a postero-medial fragment of skull. The extensive secondary palate with the internal narial opening approximately in third quarter of ventral skull length of this skull is shared with Erquelinnesia Dollo, 1887, but the extreme palatal elongation of this skull is built in a different way from that of the European genus. Other characters like the palatines not fused in the midline behind vomer in ventral view and the high and rounded skull are shared with Osteopygis Cope, 1868. While other characters (skull size, the angle of basisphenoidal crest, palatal width measured level with the pterygoid process, and the presence or absence of a post-coanal crest) suggest a generic distinction between the European, North American and South American taxa. The taxonomic differences between South American Pacific (assigned to the genus Osteopygis) and Atlantic species (referred to the new genus Pampaemys) of osteopygines are remarkable.