Taxonomic revision of the genus Mesechinus (Mammalia: Erinaceidae) with description of a new species.

Hedgehogs in the genus Mesechinus (Family Erinaceidae), which include two currently recognized species ( M. dauuricus and M. hughi ), are distributed from northeast Mongolia to the upper Amur Basin in Russia and adjacent areas in northeast and northern China. In recent years, a population of Mesechinus hedgehogs was discovered from Mt. Gaoligong, southwestern Yunnan, China, far from the known distribution range of the genus. Furthermore, these hedgehogs are the only known population to be distributed at elevations higher than 2 100 m and in sympatry with gymnures. To evaluate the taxonomic status of these hedgehogs, we examined specimens representing Mesechinus taxa in China and further conducted morphometric and karyotypic analyses. Our results supported the existence of four species in China. Specifically, we identified the hedgehogs from Mt. Gaoligong as a new species, Mesechinus wangi sp. nov., and recognized M. miodon , previously considered as a synonym of either M. dauuricus or M. hughi , as a distinct species. Interestingly, we observed a supernumerary M4 on all specimens of Mesechinus wangi sp. nov., which is an extremely rare event in the evolution of mammalian dentition.