Only two whole specimens of Australia's short-tailed hopping-mouse (Notomys amplus) were found before the species became extinct in 1896. A Gap in Nature: Discovering the World's Extinct Animals by Tim Flannery and artist Peter Schouten (Atlantic Monthly Press, $34.95) catalogues the 103 species of mammal, bird or reptile known to have become extinct between 1500 and 1999.