Systematics of South American snail-eating snakes (Serpentes, Dipsadini), with the description of five new species from Ecuador and Peru

Abstract

A molecular phylogeny of the Neotropical snail-eating snakes (tribe Dipsadini) is presented including 43 (24 for the first time) of the 77 species, sampled for both nuclear and mitochondrial genes. Morphological and phylogenetic support was found for four new species of <i>Dipsas</i> and one of <i>Sibon</i>, which are described here based on their unique combination of molecular, meristic, and color pattern characteristics. <i>Sibynomorphus</i> is designated as a junior subjective synonym of <i>Dipsas</i>. <i>Dipsas latifrontalis</i> and <i>D. palmeri</i> are resurrected from the synonymy of <i>D. peruana</i>. <i>Dipsas latifasciata</i> is transferred from the synonymy of <i>D. peruana</i> to the synonymy of <i>D. palmeri</i>. A new name, <i>D. jamespetersi</i>, is erected for the taxon currently known as <i>Sibynomorphus petersi</i>. Re-descriptions of <i>D. latifrontalis</i> and <i>D. peruana</i> are presented, as well as the first photographic voucher of an adult specimen of <i>D. latifrontalis</i>, along with photographs of all known Ecuadorian Dipsadini species. The first country record of <i>D. variegata</i> in Ecuador is provided and <i>D. oligozonata</i> removed from the list of Peruvian herpetofauna. With these changes, the number of Dipsadini reported in Ecuador increases to 22, 18 species of <i>Dipsas</i> and four of <i>Sibon</i>.