Scientist Kris Helgen holds an Eastern long-beaked echidna in Indonesia's Foja Mountains (map) in a file picture. The elusive egg-laying species is one of the rarest and most genetically unique mammals on the planet, according to the Zoological Society of London's 2010 EDGE (Evolutionarily Distinct, Globally Endangered) list, released November 19. (Take an endangered-animals quiz.)
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