Nuevos registros de Lagostomus Brookes, 1828 (Rodentia, Chinchillidae) en el Mioceno tardío de Argentina y su importancia bioestratigráfica

In this work, we present two new records of Lagostomus from the late Miocene of Argentina. A right mandible from the Huachipampa Formation (Loma del Camello, San Juan Province) is assigned to Lagostomus telenkechanum, previously recorded in the Arroyo Chasicó Formation (Chasicoan Stage/Age, late Miocene; Arroyo Chasicó, Buenos Aires Province). A skull fragment from the Cerro Azul Formation (Salinas Grandes de Hidalgo, La Pampa Province) is referred to L. pretrichodactyla, previously recorded in several units assigned to the Huayquerian Stage/Age (late Miocene) in Catamarca and Mendoza provinces, and sediments of uncertain age in Buenos Aires Province. The presence of L. telenkechanum in the Huachipampa Formation supports a Chasicoan age for this unit, which corroborates previous hypotheses, and extends the area of distribution of this species. The presence of L. pretrichodactyla in the Cerro Azul Formation suggests a late Miocene age (probably Messinian) for this unit, at least at Salinas Grandes de Hidalgo, supporting previous hypothesis. These new records allow recognizing the biostratigraphic value of Lagostomus to a higher geographic scale than previously considered.