A taxonomic revision of Scinax nebulosus (Anura: Hylidae) with the revalidation of Scinax cynocephalus and the description of three new species

Ramos A.R.L.; Fouquet A.; Roberto I.J.; Perez R.; Ferrão M.; De Carvalho V.T.; Almeida A.P.; Gordo M.; Dantas S.P.; Chaparro J.C.; De Moura G.J.B.; Ávila R.W. · Journal of Vertebrate Biology (2026) · DOI: 10.25225/jvb.26059

Resumen

Abstract.– The Spix's snouted treefrog Scinax nebulosus is one of 13 recognised species in the Scinax rostratus group, distributed from the Guiana region through eastern and southwestern Amazonia to north-eastern Brazil. Previous molecular studies identified up to five evolutionary lineages, raising taxonomic uncertainties. Here, we integrate mitochondrial (16S rRNA, n = 121), morphological (n = 587), and bioacoustic (n = 335) data to test species boundaries within the S. nebulosus complex. DNA-based delimitation recovered seven operational taxonomic units (OTUs), six of which were supported by morphological and bioacoustic evidence and thus recognised as confirmed candidate species (CCS). Two OTUs correspond to the nominal species S. nebulosus and S. constrictus. The lineage from the Guiana region corresponds to Scinax cynocephalus (Hyla cynocephala), which we resurrect from synonymy with S. nebulosus. The remaining three CCS are described as new species, being one from the northern portion of north-eastern Brazil, another from the Xingu-Tapajós interfluve and the region north of the lower River Amazon, and another from southwestern Brazilian and Bolivian Amazonia. Given acoustic divergence among populations from north-eastern Brazil, we suspect the existence of additional species or introgression, which deserves further investigation using genomic data and finer-scale phenotypic examination.