A new species of the genus Soriculus (Soricidae, Eulipotyphla , Mammalia) from Medog in the eastern Himalaya

Himalayan shrews of the genus Soriculus (Soricidae, Eulipotyphla), currently represented by four nominal species, are endemic to the Himalayas and the Gaoligong Mountains. In April 2022 and April 2023, a total of 10 specimens of Soriculus were collected from Beibeng and Damu, Medog County, Tibet, China. The morphology of the specimens was compared with the four recognised species of the genus Soriculus. Additionally, two mitochondrial (Cyt b and 12S) and three nuclear (APOB, BRCAI and RAG2) genes were sequenced to test the phylogenetic relationships of these specimens with the other species. Our results indicate that these specimens represent a distinct species, Soriculus beibengensis sp. nov., which is formally described here. The new species is distinguished from the other Soriculus species by the combination of darker pelages, smaller size, the relatively stubby nasal and the widened posterior processes of incisors. Phylogenetic analyses revealed the new species is sister to S. minor. The p-distance of Cyt b gene between S. beibengensis sp. nov. and other nominal Soriculus species ranges from 9.1-16.3%. This new species has a known distribution at an elevation of 1,500-2,125 m in Medog County, Tibet, China. The discovery of this new species from Medog County has important implications for interpreting small mammal biogeographic patterns in the eastern Himalaya and the mountain chains of south-west China.