A new Andean Toad of the genus Osornophryne (Amphibia: Anura: Bufonidae) from northwestern Ecuador, with taxonomic remarks on the genus

We describe a new species of Andean toad of the genus Osornophryne from montane cloud forests of northwestern Ecuador between 2500–2750 m above sea level. The new species is characterized by moderately large size (snout-vent length 32.5–36.0 mm in adult females, 21.1–23.2 mm in adult males), dorsal skin highly rugose with scattered irregular warts, dorsolateral ridges of round or oblong glandular warts, venter with clusters of flattened pustular warts, angular rostrum shaped like a four-sided pyramid protruding in dorsal and lateral views but not forming a proboscis, smooth borders of transverse processes of presacral vertebrae, a dark brown dorsum in life with ochre-brown warts, dorsolateral ridges maroon-brown, and abundant pale salmon spots on the venter. We suggest that it be classified as Endangered under IUCN criteria, because of its small distributional, narrow altitudinal range subjected to habitat loss and fragmentation. We discuss different aspects of taxonomy, natural history, and distribution of the different species of Osornophryne. In particular, we comment on the importance of morphological, chromatic, and molecular analyses that take into consideration ontogenic and dimorphic variation among species of Osornophryne.