Redescription of Plagiopholis styani (Serpentes, Pseudoxenodontidae), with description of two new species from China

During a long period, the genus Plagiopholis included four species and was extremely scarce. One of the members, Plagiopholis styani Boulenger, 1893, was treated as a single species widely distributed in the Dongyang domain of China. However, after new samplings of this species and examination of historical collection specimens, combined with molecular phylogenetic results based on two mitochondrial gene fragments ( CO1 and Cyt b ) and morphological comparisons of different populations, we found distinct divergences among them. Based on these results, we made the following taxonomic decisions and described the taxa in detail: (1) the populations from the type locality and adjacent areas such as Zhejiang, Anhui, and northeastern Jiangxi were considered Plagiopholis styani sensu stricto; (2) the population from Hunan Province is herein described as a new species, Plagiopholis acuta sp. nov. ; (3) the populations from Sichuan and Guizhou provinces are also described herein as a new species, Plagiopholis pluvialis sp. nov. This study brings the total number of Plagiopholis to six and highlights the importance of documenting the cryptic diversity of small-bodied snakes in East Asia’s fragmented montane ecosystems.