Four New Species of Direct-Developing Frogs, Genus Oreobates (Anura: Strabomantidae), from Peru

The Peruvian Andes harbor one of the most geographically complex and biologically diverse regions of the Tropical Andes, yet several microbasins and mountain ridges remain poorly surveyed for amphibians. Here, we describe four new species of the terrestrial-breeding frog genus Oreobates from the departments of Amazonas, San Martín and Huánuco, Peru, based on morphology, coloration, and molecular phylogenetic analyses. The new species inhabit humid montane and premontane forests of the upper basin of the Huallaga River. The new taxa differ from congeners by combinations of body size, skin texture, digital morphology, coloration, and iris pattern. Phylogenetic analyses recovered the new species within distinct lineages of Oreobates, supporting their recognition as independent evolutionary entities. Our results further highlight the role of Andean topography, especially dry inter-Andean valleys associated with the Marañón, Apurímac, and Mantaro systems, as important barriers shaping diversification in Andean amphibians. These discoveries emphasize the underestimated diversity of Oreobates in the Peruvian Yungas and reinforce the importance of continued taxonomic exploration of the Andean ecosystems.