A New Genus and Species of Phyllotine Rodent (Rodentia: Muridae: Sigmodontinae: Phyllotini) from South America

A new genus of phyllotine rodent is described. One species from northwestern San Luis Province and southeastern San Juan Province, Argentina is included. This new genus is compared with species of Eligmodontia, Calomys, Andalgalomys, and Graomys. External, cranial, and dental characters indicate that the new genus is most closely related to Calomys and Eligmodontia. The new genus may be distinguished using both quantitative and qualitative characters. The discovery of a new genus of Sigmodontine rodent specialized for desert environments in Argentina is the second in 15 years and underscores the need for further faunal work in arid areas of South America.