Paramyocastor diligens (Rodentia, Hystricomorpha) from Las Cañas formation (Pliocene), northwestern Argentina

Abstract

We describe the first fossil record of Paramyocastor diligens (Echimyidae, Octodontoidea) from the Pliocene of Las Cañas Formation (western Santiago del Estero Province, Argentina). The new record of this species increases its geographical distribution, previously known from Catamarca, Entre Ríos, and Buenos Aires Provinces. The examined materials correspond to a fragmentary hemimandible with m2-m3 and an isolated lower molar, which provide information on the occlusal morphology of Paramyocastor diligens in early ontogenetic stages.