Abstract
BACKGROUND: Boulenophrys shuichengensis (Tian & Sun, 1995) has for a long time been a subject of taxonomic ambiguity due to rare field records and a lack of molecular data from its type locality. NEW INFORMATION: To address this, we integrated molecular, morphological and type locality survey data: three tadpoles were collected from the type locality and seven adult males from Weixin County, Yunnan Province, China. Phylogenetic analyses using concatenated 16S rRNA and COI sequences revealed that tadpoles from the type locality together with specimens from Weixin (Yunnan), Dafang (Guizhou) and Chongqing, formed a strongly supported monophyletic clade with no significant genetic divergence (0-0.3%). Morphological comparion further showed that both the adult specimens from Weixin and tadpoles from the type locality of B. shuichengensis were consistent with the original species description. Our findings: (1) provide the first validated molecular data for B. shuichengensis from its type locality, therefore clarifying its taxonomic status, while also offering a detailed morphological account of its tadpoles.; (2) confirm Weixin as a new Yunnan distribution record, extending the species' range northwards by ~ 200 km; (3) verify that populations from Dafang (Guizhou) and Chongqing are conspecific, indicating a wider Yunnan-Guizhou Plateau distribution. Phylogenetically, B. shuichengensis is the sister taxon to B. caudoprocta, with both species forming a clade within the B. boettgeri group.