Unexpected diversity in west-central Argentina: A new marsh rat of the genus Holochilus (Cricetidae, Sigmodontinae). Journal of Mammalogy.

PARDIÑAS, U. F. J., P. TETA, D. VOGLINO AND F. J. FERNÁNDEZ.

JOURNAL OF MAMMALOGY

ALLIANCE COMMUNICATIONS GROUP DIVISION ALLEN PRESS

Lugar: Lawrence; Año: 2013 vol. 91 p. 231 - 240

0022-2372

Based on an adult individual obtained in the decade of 1950 plus three mandibles of latest Holocene age, we describe a new living species of the amphibious rat Holochilus (Sigmodontinae, Oryzomyini) from west-central Mendoza province, Argentina. The new species is characterized by its short tail, broad zygomatic plate with rounded anterior-superior corner, bony palate without excrescences, large mesolophostyle in the upper first molars and complex upper third molar shorter than second and lacking the hypoflexus. The morphological traits displayed by this new Holochilus combine features observed both in H. brasiliensis and H. sciureus groups with other unique among the genus (e.g., absence of hypoflexus). This new species is the southernmost expression of the genus along the western side of its current range and seems to be isolated in the middle course of the Atuel river. The finding reported here uncovers and highlights unexpected diversity in southern South American arid lands.