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The Sumatran rhinoceros, also known as hairy rhinoceros or Asian two-horned rhinoceros (''Dicerorhinus sumatrensis''), is a rare member of the family Rhinocerotidae and one of five extant rhinoceroses. It is the only extant species of the genus ''Dicerorhinus''. It is the smallest rhinoceros, although it is still a large mammal. This rhino stands high at the shoulder, with a head-and-body length of and a tail of . The weight is reported to range from , averaging , although there is a single record of a specimen. Like both African species, it has two horns; the larger is the nasal horn, typically , while the other horn is typically a stub. A coat of reddish-brown hair covers most of the Sumatran rhino's body. Members of the species once inhabited rainforests, swamps, and cloud forests in India, Bhutan, Bangladesh, Myanmar, Laos, Thailand, Malaysia, Indonesia, and China. In historical times, they lived in southwest China, particularly in Sichuan.〔Chapman, Jan (1999) ''The Art of Rhinoceros Horn Carving in China''. Christie's Books, London. ISBN 0-903432-57-9. p. 27〕〔Schafer, Edward H. (1963) ''The Golden Peaches of Samarkand: A study of T'ang Exotics''. University of California Press. Berkeley and Los Angeles. p. 83〕 They are now critically endangered, with only six substantial populations in the wild: four on Sumatra, one on Borneo, and one in the Malay Peninsula. Their numbers are difficult to determine because they are solitary animals that are widely scattered across their range, but they are estimated to number fewer than 100. Survival of the Peninsular Malaysia population is in doubt, and one of the Sumatran populations may already be extinct. Total numbers today may be as low as 80.〔("Sumatran rhino numbers revised downwards" ). ''Save The Rhino''. 18 March 2012.〕 In 2015, researchers announced that the Eastern Sumatran rhinoceros is extinct from north part of Borneo (Sabah, Malaysia).〔(【引用サイトリンク】title=Sumatran Rhino vanishes from M'sian jungles )〕 The Sumatran rhino is a mostly solitary animal except for courtship and offspring-rearing. It is the most vocal rhino species and also communicates through marking soil with its feet, twisting saplings into patterns, and leaving excrement. The species is much better studied than the similarly reclusive Javan rhinoceros, in part because of a program that brought 40 Sumatran rhinos into captivity with the goal of preserving the species. The program was considered a disaster even by its initiator; most of the rhinos died and no offspring were produced for nearly 20 years, representing an even worse population decline than in the wild. == Taxonomy and naming == The first documented Sumatran rhinoceros was shot outside Fort Marlborough, near the west coast of Sumatra, in 1793. Drawings of the animal, and a written description, were sent to the naturalist Joseph Banks, then president of the Royal Society of London, who published a paper on the specimen that year. In 1814, the species was given a scientific name by Johann Fischer von Waldheim, a German scientist and curator of the State Darwin Museum in Moscow, Russia. The scientific name ''Dicerorhinus sumatrensis'' comes from the Greek terms ' (, meaning "two"), ' (, meaning "horn"), and ' (, meaning "nose"). ''Sumatrensis'' signifies "of Sumatra", the Indonesian island where the rhinos were first discovered. Carl Linnaeus originally classified all rhinos in the genus, ''Rhinoceros''; therefore, the species was originally identified as ''Rhinoceros sumatrensis''. Joshua Brookes considered the Sumatran rhinoceros, with its two horns, a distinct genus from the one-horned ''Rhinoceros'', and gave it the name ''Didermocerus'' in 1828. Constantin Wilhelm Lambert Gloger proposed the name ''Dicerorhinus'' in 1841. In 1868, John Edward Gray proposed the name ''Ceratorhinus''. Normally, the oldest name would be used, but a 1977 ruling by the International Commission on Zoological Nomenclature established the proper genus name as ''Dicerorhinus''.〔〔International Commission on Zoological Nomenclature (1977). "Opinion 1080. Didermocerus Brookes, 1828 (Mammalia) suppressed under the plenary powers". ''Bulletin of Zoological Nomenclature'', 34:21–24.〕 The three subspecies are: ''D. s. sumatrensis'', known as the Western Sumatran rhinoceros, has only 75 to 85 rhinos remaining, mostly in the national parks of Bukit Barisan Selatan and Gunung Leuser in Sumatra, but also live in Way Kambas National Park in small numbers. 〔 None remaining may live in Peninsular Malaysia. The main threats against this subspecies are habitat loss and poaching. A slight genetic difference is noted between the western and eastern Sumatran rhinos.〔van Strien, N.J., Manullang, B., Sectionov, Isnan, W., Khan, M.K.M, Sumardja, E., Ellis, S., Han, K.H., Boeadi, Payne, J. & Bradley Martin, E. 2008. (Dicerorhinus sumatrensis. In: IUCN 2011. IUCN Red List of Threatened Species ). Version 2011.2.〕 The rhinos in Peninsular Malaysia were once known as ''D. s. niger'', but were later recognized to be similar to the rhinos on western Sumatra. ''D. s. harrissoni'', known as the Eastern Sumatran rhinoceros or Bornean rhinoceros, was once common throughout Borneo; now, only about 10 individuals are estimated to survive.〔 The known population on Borneo lives in Sabah, while video evidence from camera traps have also confirmed their presence in East Kalimantan.〔(Camera traps produce first ever hard evidence of Sumatran rhino population in Kalimantan forests ). WWF-Indonesia. 2 October 2013.〕 Reports of animals surviving in Sarawak are unconfirmed.〔 This subspecies is named after Tom Harrisson, who worked extensively with Bornean zoology and anthropology in the 1960s. The Bornean subspecies is markedly smaller than the other two.〔 The eastern Sumatran rhinoceros has recently been declared extinct in the wild and only has three individuals (1 male and 2 females) left captive in Sabah.〔http://news.mongabay.com/2015/0423-hance-sumatran-rhino-sabah-extinct.html〕 ''D. s. lasiotis'', known as the Northern Sumatran rhinoceros or Chittagong rhinoceros, once roamed in India and Bangladesh, but has been declared extinct in these countries. Unconfirmed reports suggest a small population may still survive in Burma, but the political situation in the country has prevented verification.〔 The name ''lasiotis'' is derived from the Greek for "hairy-ears". Later studies showed their ear-hair was not longer than other Sumatran rhinos, but ''D. s. lasiotis'' remained a subspecies because it was significantly larger than the other subspecies.〔 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「Sumatran rhinoceros」の詳細全文を読む スポンサード リンク
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