A new species of Dendrelaphis Boulenger, 1890 (Squamata: Colubridae) from Thailand and Myanmar

A new species of the colubrid genus Dendrelaphis Boulenger 1890 is described. Dendrelaphis nigroserratus sp. nov. occurs in a part of West Thailand as well as in the extreme south of Myanmar. Morphologically, D. nigroserratus sp. nov. is similar to D. cyanochloris (Wall, 1921) with which it occurs sympatrically. It is distinguished from the latter by its highly conspicuous neck coloration, high incidence of paired postparietal shields and its much larger size. In coloration, it resembles D. striatus (Cohn, 1906) from which it is distinguished by several aspects of its morphology. The discovery of D. nigroserratus sp. nov. underscores the notion that the hilly western parts of Thailand are in need of further exploration.