A unique, Late Oligocene shrew-like marsupial from western Argentina and the evolution of dental morphology

摘要: We describe a new metatherian mammal, Fieratherium sorex gen. et sp. nov., found in western Argentina (Quebrada Fiera locality, southern Mendoza Province), Late Oligocene deposits (Agua de la Piedra Formation, Deseadan age). The only known specimen is juvenile with fragments of both dentaries, the right maxilla and fragment left premaxilla dentition. loci number teeth preserved suggest dental formula I?3/i3, C1/c1, P3/p3, M?3/m?3. has convergent shrew-like appearance unique combination features among metatherians other South American mammals Palaeogene age, including well-known faunas Patagonia. An analysis its phylogenetic affinities suggests that sister-group Paucituberculata. As already described by authors for several mammalian taxa, mainly Patagonian fossil record offers little information to understanding evolution northern lineages. ma...