On the rare species Amphinectomys savamis Malygin 1994 (Rodentia, Cricetidae, Sigmodontinae): new record and morphological considerations

Sorting specimens at the Museum National d'Histoire Naturelle, Paris, we recovered a presumable specimen of Amphinectomys; to assess its identity, we compared this new specimen with the holotype of Amphinectomys savamis and with a syntopic sample of Nectomys apicalis. The Ecuadorean Amphinectomys differs discretely from the holotype in a few cranio-dental traits and from N. apicalis in many and more evident traits. The holotype is larger than the new specimen, and neither specimen of Amphinectomys has similar proportional dimensions in comparison with N. apicalis. Therefore, we identified the Ecuadorean specimen as A. savamis, acknowledging some level of intraspecific geographic variation and extending its current known distribution northwestwards.