Multilocus phylogeny and morphological analyses illuminate overlooked diversity of Soriculus (Mammalia: Eulipotyphla: Soricidae), with descriptions of two new endemic species from the eastern Himalayas

The genus Soriculus is currently recognized as monotypic, containing only one species, Soriculus nigrescens, which is distributed mainly in the Himalayas and the southern Hengduan Mountains. The taxonomy of Soriculus is ambiguous due to insufficient taxonomic sampling. We conducted extensive surveys of Soriculus across the Himalayas and Hengduan Mountains. We sequenced two mitochondrial and three nuclear genes, and the complete mitochondrial genomes of several selected specimens to infer the phylogenetic relationships of Soriculus and also analysed their morphological and morphometric variations. Our results indicate monophyly of Soriculus, and the diversity of the genus is greatly underestimated. We described two new species, Soriculus nivatus sp. nov. and Soriculus medogensis sp. nov., and elevated S. minor as a distinct species. Additionally, we found another putative new species of Soriculus in Medog County; however, we did not formally describe it because only one specimen was collected. Divergence time estimates suggest that the global cooling and desiccating events around the Miocene/Pliocene and Pliocene/Pleistocene boundaries and the Pleistocene climatic oscillations may have played major roles in the diversification of Soriculus. Our results highlight the overlooked diversity of small mammals in the eastern Himalayas, which warrants further surveys and taxonomic studies.