摘要The Hengduan Mountains Region(HMR)in China,a globally significant biodiversity hotspot,has garnered attention for its potential to harbor cryptic species within the Asian pit viper genus Gloydius Hoge&Romano-Hoge,1981.Based on comprehensive morphological comparisons and molecular phylogenetic analysis of the Gloydius strauchi complex,this study identified a previously unrecognized species of Asian pit viper.Discovered in the upper Lancang(Mekong)hot dry valley of Xizang,China,this species is geographically proximate to G.huangi but exhibits clear morphological distinctions from other members of the genus,representing the second Gloydius species identified along the upper Lancang River.We describe here this new species and highlight the significance of skull and hemipenis morphology,which were instrumental in its diagnosis and in resolving taxonomic boundaries and ambiguities within the G.strauchi complex.This study provides insights into the phylogenetic relationships and evolutionary history of this newly described species,enhancing our understanding of diversification patterns in this genus.