Ctenophryne aterrima (common name: Costa Rica Nelson frog, reflecting its earlier placement in Nelsonophryne) is a species of frog in the family Microhylidae. It is found in northwestern Ecuador, the Andes of Colombia, and lowland and premontane zones of Panama and Costa Rica to about above sea level. Description Ctenophryne aterrima are very robust-bodied frogs with short limbs and a small, pointed head. They are moderately sized, with males growing to and females to in snout–vent length. The skin of the dorsum is smooth and uniformly black to very dark grey in color; the ventral surface is dark brown. The eye is black. Habitat and conservation Ctenophryne aterrima is a secretive and nocturnal leaf-litter species that is rarely seen. Its natural habitats are humid lowland and montane forests. Adults can be found under fallen logs and other debris. They breed in swamps and shallow pools on the forest floor. The species is not threatened, but habitat loss caused by agricultural development, plantations, illegal crops, logging, and human settlement, and pollution resulting from the spraying of illegal crops remain possible threats. References aterrima Amphibians of the Andes Amphibians of Colombia Amphibians of Costa Rica Amphibians of Ecuador Amphibians of Panama Taxa named by Albert Günther Amphibians described in 1901 Taxonomy articles created by Polbot