The oldest sigmodontine rodent revisited and the age of the first South American cricetids

• DOI: 10.1017/jpa.2018.74
• Publication Date: 2018-12-17T09:34:06Z
• Authors: Franck Barbière; Pablo E. Ortiz; Ulyses F.J. Pardiñas
• Keywords: Tribe; Sigmodontinae

Abstract New fossil material of Auliscomys formosus Reig 1978 allows restudy the oldest known South American representative subfamily Sigmodontinae. Description was based on a fragmentary dentary exhumed from Monte Hermoso Formation central Argentina. Previous studies allocated A. to early Pliocene. A reevaluation dental and cranial morphology, including for first time upper dentition, inclusion in phylogenetic analysis tribe Phyllotini indicate that represents new genus, Kraglievichimys . shares mosaic characters with living Osgood, 1915 Loxodontomys 1947. The taxonomic reassignment possibility may be younger than Pliocene age provide understanding cricetid diversification America. Estimates sigmodontine ancestry by molecular approaches are biased toward older ages, whereas this interpretation history K. suggests sigmodontines spans less 4 million years. UUID: http://zoobank.org/49dd8f60-56b1-4e8a-a044-6cea3a1bd52b