This study examines the phylogenetic relationships and taxonomic status of Ansonia sp. Usun Apau using morphological, morphometric, and genetic analyses. The phylogenetic hypothesis obtained is based on a larger sample of Ansonia than that featured in previous studies and is used to discuss the evolutionary and biogeographic relationships between this OTU and related taxa. As the result of the investigation, we provide a formal description of Ansonia sp. Usun Apau as a new species of Ansonia. In addition, we discuss the contribution of morphometric measurements to the diagnosis and determination of cryptic species (according to the definition of Bickford et al. 2006) within this genus.