Re-interpreting the origin and diversification of the rodent genus <i>Eospalax</i> (Spalacidae, Rodentia) with description of a new species

Abstract The zokor genus Eospalax includes seven recognized species, distributed from the south-western Hengduan Mountains to the north-eastern Loess Plateau. While Eospalax was previously thought to have originated in the Qinling–Daba Mountains or North China, the discovery of Eospalax muliensis rendered this conclusion controversial. Between 1991 and 2024, faunal surveys in the northern Hengduan Mountains collected 17 conspecific zokor specimens that display distinct morphological traits compared to other species, suggesting that they may represent a separate taxon. High-depth whole-genome sequencing confirmed these specimens form a monophyletic group, supported by genetic distances derived from both the whole nuclear genome and the Cytb gene. Principal component analysis of 18 skull measurements from 90 individuals across eight species has revealed notable morphological differences between these specimens and their congeners. Molecular and morphological evidence together suggest that these specimens represent a new species, which we designate as Eospalax minshanensis sp. nov. This species, part of the high-altitude lineage, diverged from other zokors at 2.80 Mya (95% CI = 2.34–3.28 Mya). With the discovery of the new species, our findings further suggest that the genus Eospalax originated in the Hengduan Mountains.