Molecular systematics of racers, whipsnakes and relatives (Reptilia: Colubridae) using mitochondrial and nuclear markers

Four protein-encoding mitochondrial genes (cytochrome b, NADH-dehydrogenase subunits 1, 2 and 4) and one nuclear (c-mos) gene were sequenced to infer phylogenetic relationships among Old and New World representatives of racers and whipsnakes, Coluber (sensu lato). New World Coluber (Coluber sensu stricto, including Masticophis) and Salvadora proved to have affinities with the Old World non-racer colubrine genus Ptyas (and possibly Elaphe s.l. and Coronella), whereas Old World 'Coluber' form several basally related clades; these are (1) Hemorrhois(Spalerosophis-Platyceps); (2) Hierophis, with Eirenis nested within this paraphyletic genus and (3) 'Coluber' dorri as the sister taxon to Macroprotodon cucullatus. The position of 'Coluber' zebrinus along with Hemerophis socotrae located at the base of the Old World racer radiation forming the possible sister group to all remaining Palearctic racers and whipsnakes remains less well supported. Nevertheless, inter- and subgeneric relationships among many of the Old World racer groups have been resolved.