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The Asian or Asiatic elephant (''Elephas maximus'') is the only living species of the genus ''Elephas'' and is distributed in Southeast Asia from India in the west to Borneo in the east. Three subspecies are recognised—''Elephas maximus maximus'' from Sri Lanka, the Indian elephant or ''E. m. indicus'' from mainland Asia, and ''E. m. sumatranus'' from the island of Sumatra.〔 Asian elephants are the largest living land animals in Asia. Since 1986, ''E. maximus'' has been listed as endangered by IUCN as the population has declined by at least 50% over the last three generations, estimated to be 60–75 years. Asian elephants are primarily threatened by degradation, fragmentation and loss of habitat, and poaching. In 2003, the wild population was estimated at between 41,410 and 52,345 individuals. Female captive elephants have lived beyond 60 years when kept in semi-natural surroundings, such as forest camps. In zoos, elephants die at a much younger age and are declining due to a low birth and high death rate. The genus ''Elephas'' originated in Sub-Saharan Africa during the Pliocene, and ranged throughout Africa into southern Asia.〔Haynes, G. (1993). (''Mammoths, mastodonts, and elephants: biology, behavior, and the fossil record'' ). Cambridge University Press, Cambridge, ISBN 0521456916〕 The earliest indications of captive use of Asian elephants are engravings on seals of the Indus Valley civilization dated to the third millennium BC.〔Sukumar, R. (1993). (''The Asian Elephant: Ecology and Management'' ) Second edition. Cambridge University Press. ISBN 0-521-43758-X〕 == Characteristics == In general, the Asian elephant is smaller than the African elephant and has the highest body point on the head. The back is convex or level. The ears are small with dorsal borders folded laterally. It has up to 20 pairs of ribs and 34 caudal vertebrae. The feet have more nail-like structures than those of African elephants—five on each forefoot, and four on each hind foot.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Asian elephant」の詳細全文を読む スポンサード リンク
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