Abstract:In July 2022, a Megophryidae specimen was collected during a field investigation in Wuling Mountain Nature Reserve, Qianjiang District, Chongqing Municipality (Fig. 1). The aim of this study is to conduct morphological and phylogenetic analyses to identify the species. Morphological characteristics of the discovered species from Chongqing were comparatively analyzed with those of Boulenophrys caudoprocta from Hunan. Phylogenetic analyses were performed by amplifying mitochondrial 16S rRNA and COI genes and obtaining information on the 16S rRNA and COI genes of 22 Boulenophrys species from the NCBI GenBank database (Table 1). Corresponding sequences for Xenophrys glandulosa and X. mangshanensis were also downloaded and used as outgroups. Maximum likelihood phylogenetic tree was constructed using IQ-TREE, and Bayesian tree was constructed using MrBayes 3.2.1. The best-fit model was determined using the Bayesian inference criteria (BIC) computed by ModelFinder. The results of the morphological comparison between Chongqing and Hunan samples appeared to be similar (Fig. 2). The snout vent length of the female species discovered in Qianjiang District (78.2 mm) was slightly longer than that of topotype HNUL 090808dp (77.8 mm), but was slightly shorter than that of the B. caudoprocta specimen from Houhe National Nature Reserve (80.5 mm) (Table 2). Genetic analysis based on mitochondrial 16S rRNA and COI genes revealed that the B. caudoprocta group species in Qianjiang District of Chongqing and the group species from Badagongshan Nature Reserve of Hunan clustered into one branch (Fig. 3). For both 16S rRNA and COI gene sequences, the uncorrected p- distances between B. caudoprocta specimens from Chongqing and Hunan were zero, implying an absence of genetic differentiation between the two populations. (Table 3, 4). The collected Boulenophrys specimen was identified as B. caudoprocta, which is a new record of amphibian distribution in Chongqing based on thorough morphological and phylogenetic analyses.