Integrative systematics and evolutionary history of Berylmys bowersi (Mammalia, Rodentia, Muridae)

The Bower's Berylmys (Berylmys bowersi) is one of the largest rodent species with a wide distribution range in southern China and the Indochinese Peninsula. The taxonomy and evolutionary history of the B. bowersi is still controversial and confusing. In this study, we used two mitochondrial (Cyt b and COI) and three nuclear (GHR, IRBP, and RAG1) genes to estimate the phylogeny, divergence times, and biogeographic history of B. bowersi. We also explored morphological variations among the specimens collected across China. Our phylogenetic analyses indicated that the traditional B. bowersi contains at least two species: B. bowersi and B. latouchei. Berylmys latouchei was considered a junior synonym of B. bowersi distributed in eastern China, which is confirmed to be distinguishable at specific level because of its larger size, relatively larger and whiter hind feet, and several cranial traits. The estimated split of B. bowersi and B. latouchei was at the early Pleistocene (ca. 2.00 Mya), which might be the outcome of the combined effects of climate change in the early Pleistocene and isolation by the Minjiang River. Our results highlight the Wuyi Mountains in northern Fujian, China, as a glacial refugia during the Pleistocene and call for more intensive surveys and systematic revisions of small mammals in eastern China.