Molecular Systematics and Phylogeny of Old and New World Ratsnakes, Elaphe Auct., and Related Genera (Reptilia, Squamata, Colubridae)

Abstract

The phylogenetic relationships of the Holarctic ratsnakes (Elaphe auct.) are inferred from portions of two mitochondrial genes, 12S rRNA and COI. Elaphe Fitzinger is made up of ten Palaearctic species. Natrix longissima Laurenti (type species) and four western Palaearctic species (hohenackeri, lineatus, persicus, and situla) are assigned to Zamenis Wagler. Its phylogenetic affinities with closely related genera, Coronella and Oocatochus, remain unclear. The East Asian Coluber porphyraceus Cantor is referred to a new genus. This taxon and the western European Rhinechis scalaris have an isolated position among Old World ratsnakes. Another new genus is described for four Oriental species (cantoris, hodgsonii, moellendorffi, and taeniurus). New World ratsnakes and allied genera are monophyletic. Coluber flavirufus Cope is referred to Pseudelaphe Mertens and Rosenberg. Pantherophis Fitzinger is revalidated for Coluber guttatus L. (type species) and further Nearctic species (bairdi, obsoletus, and vulpinus). Senticolis triaspis is the sister taxon of New World ratsnakes including the genera Arizona, Bogertophis, Lampropeltis, Pituophis, and Rhinocheilus. The East Asian Coluber conspicillatus Boie and Coluber mandarinus Cantor form a monophyletic outgroup with respect to other Holarctic ratsnake genera and are referred to Euprepiophis Fitzinger. Three Old World species, viz. Elaphe (sensu lato) bella, E. (s.l.) frenata, and E. (s.l.) prasina remain unassigned. The various groups of ratsnakes (tribe Lampropeltini) show characteristic hemipenis features.