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| Scinax nebulosus (Spix, 1824) from Curionópolis municipality, Pará state, Brazil (A-C) Scinax divae sp. nov. from Ipú municipality, Ceará state, Brazil, (D-F) S. galacticus sp. nov. from Alter do Chão, Santarém municipality, Pará state, Brazil, (G-I) S. guapore sp. nov. from Cotriguaçu municipality, Mato Grosso state, Brazil Ramos, Fouquet, Roberto, Perez, Ferrão, De Carvalho, Almeida, Gordo, Dantas, Chaparro, De Moura & Ávila, 2026 |
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.
KEYWORDS: cryptic diversity, Integrative taxonomy, Neotropics, Scinax rostratus group, Scinaxini
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| Specimens of Scinax nebulosus from Curionópolis municipality, Pará state, Brazil (L2, A-C), S. constrictus from Barra do Garças municipality, Mato Grosso state, Brazil (L3, D-F) and S. cynocephalus from Sipaliwini district, Suriname (L5, G-I) in life. |
Scinax nebulosus (Spix, 1824) (L2)
Scinax constrictus (Lima et al., 2005) (L3)
Scinax cynocephalus (Duméril & Bibron, 1841) stat. rev. (L5)
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| Specimens of Scinax divae sp. nov. from Ipú municipality, Ceará state, Brazil (L1 E, A-C), S. galacticus sp. nov. from Alter do Chão, Santarém municipality, Pará state, Brazil (L6, D-F) and S. guapore sp. nov. from Cotriguaçu municipality, Mato Grosso state, Brazil (L7, G-I) in life. |
Scinax divae sp. nov. (L1 East)
Etymology: The specific epithet divae is a noun in the genitive case and a matronym for the herpetologist Diva Maria Borges Nojosa, honouring her pioneering work with the herpetofauna of the brejos-de-altitude, humid highland in the state of Ceará. It also recognises her role as the director of the Núcleo Regional de Ofiologia da Universidade Federal do Ceará (NUROF-UFC), where she made significant contributions to the formation of numerous herpetologists throughout her career as a professor at the institution.
Diagnosis: The new species is characterized by: SVL 23.9-31.0 mm, x̄ = 26.3 ± 1.5 in males and 28.3-40.0 mm, x̄ = 35.3 ± 3.1 in females; males have a subovoid head (Ch.1.0) with a rounded (Ch.2.0) or nearly acute (Ch.2.1) snout in dorsal view, being rounded (Ch.3.0), nearly protruding (Ch.3.1) or protruding (Ch.3.2) in lateral view; females have a subovoid (Ch.1.0) or nearly rounded head (Ch.1.1) with a rounded (Ch.2.0) or nearly acute (Ch.2.1) snout in dorsal view, being nearly protruding (Ch.3.1) or protruding ...
Scinax galacticus sp. nov.
Etymology: The specific epithet galacticus is formed from the Latin (galactic + Latin adjectival suffix –us), derived from the Greek ‘γάλα’, ‘γάλακτος’ (gála, gálaktos = ‘milk’), meaning ‘galaxy’ or ‘pertaining to a galaxy’. The name is treated as an adjective and refers to the pattern of blotches covering almost the entire inner surface of the thighs and the heavily speckled ventral pattern observed in some specimens, resembling a starry sky.
Diagnosis: The new species is characterized by: SVL 21.9-32.4 mm, x̄ = 26.4 ± 2.3 in males and 30.8-40.7 mm, x̄ = 35.9 ± 3.3 in females; males have a subovoid head (Ch.1.0) with a rounded snout in dorsal view (Ch.2.0), being rounded (Ch.3.0) or nearly protruding (Ch.3.1) in lateral view; females have a subovoid (Ch.1.0) or nearly rounded (Ch.1.1) head with a rounded snout (Ch.2.0) in dorsal view, being rounded (Ch.3.0) or nearly protruding (Ch.3.1) in lateral view; nostrils not prominent in dorsal view (Ch.4.0); pointed tubercle on the snout absent (Ch.5.0) or slight (Ch.5.1) not forming a small proboscis; conical process on the heel indistinct (Ch.12.0) or small (Ch.12.1); females with a compound pectoral fold ...
Scinax guapore sp. nov.
Etymology: The specific epithet guapore is a noun in apposition and a toponym referring to the River Guaporé, one of the main watercourses in the region where the new species occurs. This river also marks the border between Brazil and Bolivia. The name originates from Tupi-Guarani and probably means ‘deserted valley’ or ‘river with waterfalls’.
Diagnosis: The new species is characterized by: SVL 21.3-29.2 mm, x̄ = 25.8 ± 1.9 in males and 31.0-36.3 mm, x̄ = 33.5 ± 2.1 in females; males with a subovoid head (Ch.1.0) with a rounded (Ch.2.0) or acute (Ch.2.1) snout in dorsal view, being protruding (Ch.3.2) or acute (Ch.3.3) in lateral view; females with a subovoid (Ch.1.0) or nearly rounded (Ch.1.1) head with a rounded (Ch.2.0) or acute (Ch.2.1) snout in dorsal view, being nearly protruding (Ch.3.1) or protruding (Ch.3.2) in lateral view; nostrils prominent in ...
Antônio R.L. Ramos, Antoine Fouquet, Igor J. Roberto, Renata Perez, Miquéias Ferrão, Vinícius T. De Carvalho, Alexandre P. Almeida, Marcelo Gordo, Silionamã P. Dantas, Juan C. Chaparro, Geraldo J.B. De Moura and Robson W. Ávila. 2026. A Taxonomic Revision of Scinax nebulosus (Anura: Hylidae) with the Revalidation of Scinax cynocephalus and the Description of Three New Species. Journal of Vertebrate Biology. 75 (26059), 26059.1-37. DOI: doi.org/10.25225/jvb.26059 (29 September 2026)
