A new species of snail-eater snake, genus Dipsas (Serpentes: Dipsadini), from the inter-Andean Mantaro River valley in southern Peru

We describe a new species of Dipsas Laurenti, 1768 from the inter-Andean valley of the Mantaro River in southern Peru based on external morphology and DNA sequences. The new species is most similar to coastal and Andean species from Ecuador and Peru, such as: D. georgejetti, D. jamespetersi, D. oligozonata, D. oneilli, D. oswaldobaezi, D. vagrans, D. vagus, and D. williamsi. Many of these species had previously been assigned to the genus Sibynomorphus. The new species is easily distinguished from congeneric species by lacking preoculars and by its unique scalation and coloration patterns. In addition, we assess its conservation status, categorizing the species as Least Concern, and discuss species richness of the genus Dipsas in Peru, with particular emphasis on the taxonomic status of D. peruana.