Using molecular taxonomy to identify Scinax (Anura: Hylidae): New distribution records and implications for...

Traditional morphological identification is challenging in large and diverse groups, such as the genus Scinax, which comprises about 78 species, and molecular taxonomy emerges as an efficient tool for species delimitation. We generated 164 new mitochondrial 16S rRNA sequences from Scinax individuals collected in north and central-west Brazil, covering the Amazon biome, Amazon-Cerrado transition zones, and the Pantanal. After comparison with all sequences available in GenBank, 22 references representing the closest lineages were selected for detailed analyses. These were examined through phylogenetic inferences, genetic distances, and species delimitation methods (ASAP, ABGD, GMYC, bPTP). The analyses confirmed the genetic identity of individuals belonging to Scinax acuminatus, S. boesemani, S. fuscomarginatus, S. fuscovarius, S. jolyi, S. madeirae, S. nasicus, S. nebulosus, S. proboscideus, S. similis, Scinax sp. 1, sp. 2, sp. 5, sp. 7, sp. 22, and sp. 27. This study also expanded the distribution of eight species, including described and undescribed taxa (S. jolyi, S. proboscideus, S. similis, Scinax sp. 2, Scinax sp. 5, Scinax sp. 7, Scinax sp. 21 and Scinax sp. 27), highlighting the importance of molecular approaches for clarifying biogeographic patterns. Our results reinforce the effectiveness of molecular taxonomy for Scinax identification and contribute to refining genus diversity knowledge, reducing distributional gaps in Neotropical amphibians.