Abstract
Pristimantis, a genus of direct-developing frogs within the family Strabomantidae, comprises 617 recognized species, making it the most species-rich genus of vertebrates worldwide. This group include 264 described (43% of the world) species in Ecuador, being one of the countries in the region with the highest rate of species description, greatest diversity and endemism. In this study, we analyze the phylogenetic position and describe a new Pristimantis species from the Colonso Chalupas Biological Reserve and Llanganates National Park in northeastern Ecuador, using phylogenetic, genetic, morphological, and geographic evidence. Additionally, we propose a new subgenus within Pristimantis that includes the Pristimantis prolatus and Pristimantis bicantus species groups. Our results indicate that the new species and related species form a well-supported group with significant genetic divergence based on the 16S rRNA gene (average uncorrected p-distance = 2.8-7.5%), within the Pristimantis bicantus species group. Morphologically, the new species is characterized by a black to dark-gray dorsum and marbled venter (less intense or brown in males), being endemic to the Guacamayos mountain range and the Llanganates region in the northeastern Andean foothills of Ecuador. We emphasize the importance of including topotypic specimens to analyze and compare species groups to delimiting species, like Pristimantis.