Dendrelaphis thasuni

Dendrelaphis thasuni is a bronzeback tree snake described in 2025 from a single female collected on Maragala Mountain in the Monaragala District of Uva Province, an isolated misty mountain in the south-eastern intermediate zone. Its closest relative is the stripe-tailed bronzeback, from which it differs in having an undivided, large anal plate, narrower ventral scales, and narrow blackish transverse bars along the sides spaced about an eye diameter apart. It has 13 dorsal scale rows at midbody, 153 ventral scales and 117 to 118 subcaudals. It is likely arboreal, and its colour resembles the branches it lives on (original description 2025, as summarised by Nova Taxa and The Island).

It is named for the Sri Lankan herpetologist A. A. Thasun Amarasinghe. Maragala Mountain is rich in wildlife, with 67 reptile species, 30 of them endemic, and its habitats are heavily modified by people, so the authors call for urgent conservation measures. Nothing else is yet known of its habits. No status is given for it in the Sri Lanka National Red List 2012 list checked, since it was described later.