The Zoological Society of London just announced a plan that would add the world's 100 most evolutionarily distinct species to international endangered lists. Many of them are so strange that they're often overlooked by more traditional approaches to conservation; these represent one-of-a-kind species that have few taxonomic relatives on earth. Jonathan Baille, the program's lead scientist, said "They represent entire lineages. If you were to think about Edge species in terms of the art world, it would be like losing a Mona Lisa - they are totally irreplaceable and unique." Some of these "Mona Lisas" include:
The slender loris, one of the world's smallest (and weirdest-looking) primates, whose habitat in Western Thailand and Burma are threatened by deforestation.
The hirola, also known as the "four-eyed antelope" thanks to their huge preorbital glands. Prolonged droughts have disturbed their dwindling population, which live on the arid plains between Kenya and Somalia.
The bumblebee bat, also curiously known as Kitti's Hog-Nosed Bat, the smallest mammal in the world at approximately 30mm in length and weighing less than a dime. Considered one of 12 most endangered species on the planet, the Thai government only found 160 of them living in caves despite extensive surveys in 1982.
The politely-named Golden-rumped elephant shrew (no relation to The Golden Ass of Greek lore), which is endemic to just one forest in Kenya, where is it hunted for food by locals. (The golden hindquarters, by the way, act as a distraction for potential predators; its booty is thick and protected, it's head is not.)