A New Species of the Genus Ovophis Burger in Hoge & Romano-Hoge, 1981 (Serpentes, Viperidae) from Xizang, China

In 1981, Hoge & Romano-Hoge (1981) erected the genus Ovophis, one of the most widely distributed snake groups in Asia. Its distribution ranges westward from eastern Asia to Nepal, encompassing the entire East Asia and the Indochinese Peninsula. During recent herpetological surveys conducted near Medog County, Xizang Autonomous Region, China, a previously undescribed snake species was discovered. Based on integrated morphological and molecular evidence, this species is herein described as a new taxon: Ovophis medogensis sp. nov. This new species can be distinguished from all its congeners by the following combination of characters: possesses off-white spots on the ventral surface; lacks irregular markings on the dorsal surface of the head; body short and stout, with a brown dorsal ground color bearing 19-20 irregular black butterfly-shaped blotches; presence of a brownish-orange postorbital stripe; vertically elliptical pupil, brownish-black in color; dorsal surface of the tail with white dots extending to the tail tip; infralabials: 11 (12)/11 (10); the first and second pairs of infralabials in contact with chin shields; supralabials: mostly 8, occasionally 9; ventrals: 132-138; subcaudals: 39-49, mostly paired; dorsal scale rows 23-23-19; Molecular phylogenetic analyses revealed that the new species forms a well-supported distinct lineage, with a Bayesian posterior probability (BPP) of 1.00 and an ultrafast bootstrap (UFB) value of 100. Analyses of uncorrected pairwise genetic distances based on the mitochondrial cytochrome b (Cyt b) gene showed that the genetic distances between the new species and other known species of the genus Ovophis range from 0.055 (vs. Ovophis monticola) to 0.135 (vs. Ovophis tonkinensis). The discovery of this new species further enhances our understanding of biodiversity in the eastern Himalayas and provides valuable insights into the taxonomy and evolutionary relationships of the genus.