Four new species of Pristimantis myersi group (Anura: Craugastoridae) from Carchi, Ecuador: cryptic diversity in unique and threatened high-Andean ecosystems.

The high-Andean ecosystems of the northern Andes rank among the most diverse and endemic regions on the planet. This study describes four new species of frogs in the genus Pristimantis, belonging to the myersi group. The four new species were discovered through 6 years of fieldwork (2016-2021) as part of doctoral research integrating morphological, bioacoustic, ecological, and molecular data. Phylogenetic analyses based on mitochondrial DNA (mtDNA) support the recognition of each taxon as a distinct species of Pristimantis, known for its cryptic diversity and restricted distribution. Additionally, we document changes in vegetation cover across the habitats where these species occur, underscoring the fragility of their ecosystems. This study represents the first attempt to link the distribution of these species with the spatiotemporal dynamics of vegetation cover in Carchi, showing a net loss of more than 9,000 hectares between 1985 and 2022, particularly in the western Andean foothills. Finally, our findings uncover the previously undocumented biological richness of Carchi Province and highlight the urgent need to conserve its unique and threatened high-Andean ecosystems.