Morphological Phylogeny of the Water Snake Subfamily Homalopsinae (Serpent: Colubridae)

The morphological phylogeny of the water snake subfamily Homalopsinae, containing 10 genera, of which seven are monotypic, was not reported up until now. Here fourteen morphological characters were selected for the cladistic analysis. Using software Hennig 86, two phylogenetic trees were inferred and the results showed that the subfamily Homalopsinae was divided into two groups. Compared with the molecular phylonenetic tree of Voris et al(2002), the genera Gerarda and Fordonia are sister groups in both studies; both studies also yielded the same monophyletic lineage, which contained three genera (Cerberus+Erpeton+Homalopsis). However, the position of the genus Cantoria is distinctly different with the study of Voris et al(2002).