Genetic delimitation of Pristimantis orestes (Lynch, 1979) and P. saturninoi Brito et al., 2017 and description of two new terrestrial frogs from the Pristimantis orestes species group (Anura, Strabomantidae)

Abstract

In the genus Pristimantis, species are often combined into taxonomic units called species groups. The taxonomy of these groups is frequently inaccurate due to the absence of genetic data from type series and repeated misidentifications generated by high morphological resemblance between taxa. Here, we focus on the P. orestes species group, providing the first genetic assessment of P. orestes sensu stricto from individuals collected from the type locality, with a reviewed diagnosis and description of advertisement calls. We find that two lineages previously named P. orestes are genetically distinct and should be separated into two different species. Based on genetic and morphological data, we name one of these species P. cajanuma sp. nov. This new species is morphologically distinct from other members of the group by having shagreen dorsal skin, evident dorsolateral folds, broader discs on toes and fingers and pale gray ventral coloration. Additionally, P. saturninoi is placed within the P. orestes species group based on genetic data from its type series. However, we find that one of its paratypes is genetically distinct and belongs to a clade containing a new species we name P. quintanai sp. nov. This new species is morphologically distinguished by lacking a tympanic membrane and vocal sacs in males, and by having expanded discs on toes and fingers, finely tuberculated dorsal skin and irregular white or cream spots in the groin and concealed surfaces of thighs. Our findings highlight the importance of providing genetic characterization and placement from the type series in taxonomic challenging groups, such as Pristimantis. We also suggest that the diversity of species within the P. orestes group will increase as more sampling is achieved in the southern Andes of Ecuador.