Gloyd's Hump-nosed Viper

Gloyd's hump-nosed viper, also called the Sri Lankan hump-nosed viper, is a small venomous pit viper endemic to Sri Lanka, known in Sinhala as mukalan thelissa. It was once thought that Hypnale walli and Hypnale nepa were two species, but they are now treated as one. Adults grow to 30 to 35 cm in total length, and the largest recorded male measured 38.7 cm (Wall 1921, as reported on Wikipedia). The head is conspicuously distinct from a moderately slender body (Wikipedia, general species account).

It is told from the common hump-nosed viper by a strongly upturned snout tip, caused by an extended rostral scale followed by a raised wart-like hump covered with 7 to 14 very small scales. The colour is light brown to dark brown or pale olive, flecked with darker tones, with 17 to 26 brown blotches along each side that alternate or oppose one another along the back. Nationally Endangered (Sri Lanka National Red List 2012).