Molecular phylogeny, morphological diversity, and systematic revision of a species complex of common wild rat species in China (Rodentia, Murinae)

Rats of the Niviventer niviventer species complex (NNSC) are among the most abundant small mammals in Southeast Asia and China. More than 20 species or subspecies have been reported in the scientific literature; however, this species complex remains taxonomically ambiguous. With extensive sampling and integrated information from molecular and morphological data, we examined genetic divergences and morphological differences among species within the NNSC. Analyses of molecular voucher specimens revealed that the reported geographic ranges of most NNSC species need revision. Morphological analyses demonstrated that substantial differences exist among these species. Niviventer confucianus, the NNSC species with the largest number of subspecies, showed the greatest intraspecific morphological variation. The taxonomic revision presented here establishes 2 new taxa as independent species. This species complex in China now includes 8 species: N. bukit, N. confucianus, N. coninga, N. culturatus, N. lotipes, N. niviventer, 1 new species, N. gladiusmaculus sp. nov., and a new combination N. pianmaensis comb. nov.