Pliocene freshwater isopods (Crustacea: Peracarida: Isopoda) from Jalisco, Mexico

Abstract

A new genus and species of freshwater isopod is described from Pliocene volcanic sedimentary ashes found in an ancient lake basin in the Santa Rosa Dam region, Amatitlán, Jalisco, West-central Mexico. The new isopod is represented by a few corpses and molts. Due to the relatively poor preservation, no further morphological details can be offered to the moment, but the observed features are sufficient to distinguish this isopod from any living or fossil freshwater Sphaeromatidae species. This contribution extends the stratigraphic and geographic record of fossil isopod bearing localities in Mexico, being this the youngest fossil Peracarida recorded from this country.