The clock is ticking on many animal species that are threatened with extinction, and the International Union for Conservation of Nature is the timekeeper.
The IUCN, one of the world’s foremost advocates for preserving the natural world, keeps what it calls a “red list,” an assessment of the threats faced by plants and animals. As of 2016, the 70-year-old organization’s list included 82,954 species, of which 23,928 were threatened with extinction.
24/7 Wall St. has compiled a list of the rarest and possibly extinct animals based on data from the IUCN’s red list. Most of the animals on this list have estimated populations of 250 or fewer.