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.

KEYWORDS:

• Octodontoidea
• Echimyidae
• Pliocene
• Termas de Río Hondo
• Argentina

Acknowledgments

The authors wish to express their gratitude to the Gaudioso family for their support, cooperation and funding for field trips. We thank the curators of the vertebrate paleontological collections for granting access to materials under their care: Colección Paleontológica Vertebrados Lillo (PVL), Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” (MACN), Museo de La Plata (MLP) and Museo Municipal de Ciencias Naturales “Carlos Darwin” (MD-FM). We especially thank Rodrigo Tomassini who facilitated the revision of material collected by him from Monte Hermoso Formation and deposited at the MD-FM. The authors also thank two anonymous reviewers for their helpful comments. C.C. Morgan and R. Barquez assisted with translation. Finally, we thank the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and ANPCyT, PICT 2016-2881 (AIO).

Disclosure statement

No potential conflict of interest was reported by the authors.