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Deinotherium
''Deinotherium'' ("terrible beast" derived from the Ancient Greek ''δεινός, deinos'' meaning "terrible" and ''θηρίον, therion'' meaning "beast") was a large prehistoric relative of modern-day elephants that appeared in the Middle Miocene and survived until the Early Pleistocene. During that time it changed very little. In life, it probably resembled modern elephants, except that its trunk was shorter, and it had downward curving tusks attached to the lower jaw.
==Taxonomy and evolution==
''Deinotherium'' is the type genus of the family Deinotheriidae, which evolved from the smaller, early Miocene ''Prodeinotherium''. These proboscideans represent a totally distinct line of evolutionary descent to that of other elephants, one that probably diverged very early in the history of the group as a whole. The large group to which elephants belong formerly contained several other related groups: besides the deinotheres, there were the gomphotheres (some of which had shovel-like lower front teeth), and the mastodons. Only elephants survive today.
Three species are recognized, all of great size. ''Deinotherium giganteum'' is the type species, and is described above. It is primarily a late Miocene species, most common in Europe, and is the only species known from the circum-Mediterranean. Its last reported occurrence is from the middle Pliocene of Romania (2 to 4 million BP). An entire skull, found in the Lower Pliocene beds of Eppelsheim, Hesse-Darmstadt in 1836, was 4 ft (1.2 m) long and 3 ft (0.9 meters) wide, indicating an animal exceeding modern elephants in size. ''Deinotherium indicum'' is the Asian species, known from India and Pakistan. It is distinguished by a more robust dentition and p4-m3 intravalley tubercles. ''D. indicum'' appears in the middle Miocene, and is most common in the late Miocene. It disappeared from the fossil record about 7 million years BP (late Miocene). ''Deinotherium bozasi'' is the African species. It is characterized by a narrower rostral trough, a smaller but higher nasal aperture, a higher and narrower cranium, and a shorter mandibular symphysis than the other two species. ''D. bozasi'' appears at the beginning of the late Miocene, and continues there after the other two species have died out elsewhere. The youngest fossils are from the Kanjera Formation, Kenya, about a million years old (early Pleistocene).
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
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