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| Osornophryne backshalli Reyes-Puig, Urgiles-Merchán, Ortega-Andrade, Cisneros-Heredia, Carrión-Olmedo & Yáñez-Muñoz, 2025 |
Abstract
The amphibian genus Osornophryne is endemic to the northern Andes of South America and has long been considered rare. Recent explorations in the humid montane forests of the upper Pastaza Valley have uncovered previously unknown species. Here, we describe a new Andean toad species from the central Ecuadorian Andes, identified through genetic analyses and distinctive morphological and cranial traits. Osornophryne backshalli sp. nov., from Cerro Candelaria in the upper Pastaza River basin, is closely related to O. sumacoensis from Sumaco Volcano. This new species is characterized by a uniquely short fifth toe relative to toes I–III, triangular papillae on the snout tip, an occipital fold, large subconical and conical warts on the body, dorsal surfaces Brownish Olive with Spectrum Yellow and Light Neutral Gray flecks, ventral surfaces Brownish Olive with Spectrum Yellow bright blotches. Our phylogenetic analyses revise the genus taxonomy by delimiting two well-supported clades: the Osornophryne bufoniformis species group and the Osornophryne guacamayo species group. Furthermore, we show that the Pastaza River does not constitute a geographical barrier for Osornophryne distribution. These findings emphasize the value of continued exploration to expand our understanding of this genus in the humid montane forests of the Ecuadorian Andes.
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| Comparison of the live coloration within the type series of Osornophryne backshalli sp. nov. (A) DHMECN 15260, female holotype; (B) DHMECN 18362, adult female paratype; (C) DHMECN 18364, adult male paratype; (D) DHMECN 18363, adult female paratype. photo credit: Mario H. Yánez-Muñoz (A) and Juan P. Reyes-Puig (B, C, D). |
Osornophryne backshalli sp. nov.
Osornophryne sp. nov. INABIO-Instituto Nacional de Biodiversidad (2023)
Proposed standard English name. Steve Backshall’s Andean Toad
Proposed standard Spanish name. Osornosapo de Steve Backshall
Diagnosis. Osornophryne backshalli sp. nov. is a member of clade B (O. guacamayo species group), and differs from all other species of the clade by the following combination of characters: (1) small to medium size toads (SVL = 22.08–29.68 mm in males, 30.09–35.4 mm on females; Table 2); (2) head slightly wider than long; (3) skin on dorsal surfaces and limbs finely granular with conical and subconical warts, males more tuberculated than females,ventral surfaces with subconic tubercles; (4) snout subacuminate in dorsal view, protruding in lateral profile, with pointed irregular papillae on the tip; (5) crista parotica slightly arched with finely glandular skin, posterior and oblique in relation to the orbit; zygomatic ramus of the squamosal elongated with a blunt anterior border, cultriform process with blunt anterior border; (6) glandular occipital folds present, discontinuous, dorsolateral folds absent, instead a row of discontinuous subconical tubercles on its place; (7) pelvic folds absent (8) limbs short, heels do not touch when adpressed; (9) fingers and toes with extensive and thick webbing, fingers visible, tips of Toes I, II, III almost indistinguishable, Toe V short, not elongated, slightly longer than Toe III, nuptial pads in males on the anterior part of Finger I; (10) dorsal surfaces Brownish Olive with Spectrum Yellow and Light Neutral Gray flecks, ventral surfaces Brownish Olive with Spectrum Yellow blotches; (11) short cloacal tube slightly projected medial to the thighs.
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| Life coloration and detailed dorsolateral view showing sexual dimorphism of Osornophryne backshalli sp. nov. (A) DHMECN 15260, holotype, adult female; (B) DHMECN 18364, paratype, adult female; (C) DHMECN 18364 paratype, adult male. Photo credit: Mario H. Yánez-Muñoz (A) and Juan P. Reyes-Puig (B, C). |
Etymology. The specific epithet is a patronym in honor of the explorer and television presenter Steve Backshall, of London, UK. He has raised awareness of nature around the world and has, through his patronage of the World Land Trust, contributed directly to the conservation of the Corredor de Conectividad Llanganates-Sangay, the habitat of this particular species and many others.
Juan P. Reyes-Puig, Miguel A. Urgiles-Merchán, H. Mauricio Ortega-Andrade, Diego F. Cisneros-Heredia, Julio C. Carrión-Olmedo and Mario H. Yáñez-Muñoz. 2025. New Andean Plump Toad of the Genus Osornophryne (Anura: Bufonidae) from Cerro Candelaria, Ecuador. PeerJ. 13:e19760 DOI: doi.org/10.7717/peerj.19760 [July 23, 2025]
