| Xenodermatids have been considered a subfamily of the Colubridae as well as a separate family. The species contained in the family have also been controversial, with some suggesting it contained only Oriental species, while others placed some Western Hemisphere species in the family. Here I am going to consider it to be restricted to Asia considering the recent results of Vidal et al. (Vidal et al. 2007, C. R. Biologies 330:182-187) found this group to be basal to all of the advanced snakes after the file snakes (acrochordids). The family contains at least three genera (Xenodermus, Stoliczaia, and Achalinus) which have about 12 species, and all are Asian. The common name applied to these snakes refers to the fact that the scales are almost completely fused to the underlying skin, while most snakes have one edge of the scale embedded in the underlying dermis and the other edges are free. In Xenodermus the scales have exposed skin between them. |
