The Oldest Species of Dolichotis (Rodentia, Hystricognathi) from the Pliocene of Argentina: Redescription and Taxonomic Status of “Orthomyctera” chapalmalense

The Subfamily Dolichotinae comprises two living species, Dolichotis patagonum, an emblematic component of the Patagonian fauna Argentina, and salinicola, endemic to Chaco ecoregion. These species are also considered as pertaining different genera, D. patagonum Pediolagus salinicola. oldest records come from Pliocene–Pleistocene boundary northeastern central late Pleistocene southern Brazil, northern Uruguay. Five fossil were described Holocene in Argentina (D. minor, plathycephala, major, intermedia, improla). “Orthomyctera” chapalmalense was on basis remains coast Mar del Plata Chapadmalal, Buenos Aires Province, Chapadmalal Formation (late Pliocene, 3.74–3.04 Ma). A new detailed description holotype its comparison with closely related taxa suggests that this is more genus Dolichotis, resulting combination chapalmalense. close affinities revealed by phylogenetic analyses combined molecular morphological characters corroborated previous analyses. origin lineage extends at least a million years ago, taking record back middle Pliocene. evolutionary novelties appear since marking key period for Caviidae, analyzed. Based perspective inclusion record, our data support salinicola) single genus.