New mammal and biochronological data for the Mariño Formation (Miocene) at Divisadero Largo, Mendoza (Argentina)

CERDEÑO, E.; VUCETICH, M. G.

REVISTA GEOLóGICA DE CHILE

Año: 2007 vol. 34 p. 199 - 207

0716-0208

A new significant mammal fossil from the Mariño Formation in the area of Divisadero Largo (Mendoza, Argentina) is described herein. The material consists of a mandibular fragment with the right series p4-m3 of the rodent ScleromysScleromys sp. It is compared with the Santacrucian species S. osbornianus Ameghino and S. angustus Ameghino, and with S. quadrangulatus Kramarz from the Pinturas Formation, all of them from the Santa Cruz Province. At the same time, the studied fossil presents a combination of characters that differ from those species: more transverse molars, with anterior wall slightly curved, lower degree of hypsodonty and smaller size. However, due to the great morphological variation within Scleromys, a specific determination is not provided based on a sole specimen. The presence of this genus, together with the previously studied mesotheriine, supports an early Miocene age for the middle member of the Mariño Formation.S. osbornianus Ameghino and S. angustus Ameghino, and with S. quadrangulatus Kramarz from the Pinturas Formation, all of them from the Santa Cruz Province. At the same time, the studied fossil presents a combination of characters that differ from those species: more transverse molars, with anterior wall slightly curved, lower degree of hypsodonty and smaller size. However, due to the great morphological variation within Scleromys, a specific determination is not provided based on a sole specimen. The presence of this genus, together with the previously studied mesotheriine, supports an early Miocene age for the middle member of the Mariño Formation.Kramarz from the Pinturas Formation, all of them from the Santa Cruz Province. At the same time, the studied fossil presents a combination of characters that differ from those species: more transverse molars, with anterior wall slightly curved, lower degree of hypsodonty and smaller size. However, due to the great morphological variation within Scleromys, a specific determination is not provided based on a sole specimen. The presence of this genus, together with the previously studied mesotheriine, supports an early Miocene age for the middle member of the Mariño Formation.Scleromys, a specific determination is not provided based on a sole specimen. The presence of this genus, together with the previously studied mesotheriine, supports an early Miocene age for the middle member of the Mariño Formation.