The EDGE of Existence programme highlights and conserves one-of–a-kind species that are on the verge of extinction.
We have scored the world's mammals
and amphibians according to how Evolutionarily Distinct and Globally Endangered (EDGE) they are. The top 100 in each group are highlighted here.
These are the world's most extraordinary threatened species – frogs that give birth through their skin and mammals that are immune to cyanide – yet most are unfamiliar and not currently receiving conservation attention.
Help conserve nature's most amazing animals. Find out how here.