Unveiling hidden diversity in Odorrana (Anura, Ranidae) with description of a new species from Yingjiang, China and the first national records of Odorrana heatwolei in Thailand and Vietnam

Species discovery within Odorrana has gradually increased over the years, establishing a remarkable diversity for the genus. During recent herpetological surveys, we collected specimens from Yingjiang County, Yunnan Province, China with additional samples from Thailand and Vietnam. Based on combined morphological and phylogenetic analyses, we describe a new species Odorrana sudianensis sp. nov. from Sudian Town, Yingjiang County, China and report new records of O. heatwolei for Thailand and Vietnam. Phylogenetic analyses, based on the 16S rRNA mitochondrial gene fragment, confirm the new species as a distinct evolutionary lineage with a genetic divergence ( p -distance) of 4.6% from its closest sister species O. dulongensis . Odorrana sudianensis sp. nov. is morphologically distinguishable from all its known congeners by having a robust medium adult body size, a head length longer than wide, a mottled grass-green dorsum with dark brown blotches on the posterior region, absence of dorsolateral folds and circum-marginal grooves for all finger discs expanded with lateroventral grooves. Additionally, the new species record sequences from Thailand and Vietnam nested within the O. heatwolei subclade with a low p -distance (0.0–0.5%) from topotypic sequences of O. heatwolei . Examined specimen shows morphological congruence with topotypic O. heatwolei in key diagnostic traits. Our new species and new species records increase the number of recognised species of Odorrana to 46 in China, seven in Thailand and 23 in Vietnam. We also address existing taxonomic disputes within Odorrana and provide comments and recommendations on the taxonomy of several species within the genus.