Learn about the extinct animals that once roamed the Earth, from Ice Age mammals to recent amphibians. Find out the reasons behind their extinction, such as habitat loss, hunting, climate change, and more. Established in 1964, the IUCN Red List of Threatened Species has evolved to become the world’s most comprehensive information source on the global conservation status of animal, fungi and plant species. What is Extinction? When a species becomes extinct, all its genetic heritage is lost. The species evolve into new species in order to adapt to the environmental changes or changes in the genetic heritage. Over 99% of all the species that once lived on the Earth, amounting to over five billion species, are estimated to be extinct. Extinction is the termination of an organism by the death of its last member. A taxon may become functionally extinct before the death of its last member if it loses the capacity to reproduce and recover. As a species ' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of ...
