A new limestone-associated species of wolf snake in the Lycodon fasciatus complex (Squamata: Serpentes: Colubridae) from central Vietnam

As part of our ongoing investigations into the systematics of the Lycodon fasciatus species complex, we examined specimens from the Northern Annamites (Truong Son Mountains) in central Vietnam, previously referred to as Lycodon fasciatus Anderson in the literature. Herein, we describe a new species of the genus Lycodon Fitzinger from Phong Nha-Ke Bang National Park, Quang Binh Province, central Vietnam, based on both molecular evidence derived from published phylogenetic frameworks and newly collected morphological data. The new species, Lycodon calcarophilus sp. nov., closely resembles Lycodon ruhstrati (Fischer), but can be distinguished by several morphological characters, including the loreal in contact with eye, lower ratio tail length to total length, lower number of subcaudal scales, lower number of total body scales, and lower number of body cross-bands. We provide detailed comparisons between L. calcarophilus sp. nov. with Lycodon fasciatus as currently defined and other members of the L. fasciatus group. Additionally, we provide an updated checklist of 152 species of amphibians and reptiles currently documented from Phong Nha-Ke Bang National Park.