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Camelops
''Camelops'' is an extinct genus of camel that once roamed western North America, where it disappeared at the end of the Pleistocene about 10,000 years ago. It was very closely related to the Old World Dromedary and Bactrian Camel in anatomical form. Its name is derived from the Greek κάμελος (camel) + (face), thus "camel-face."
==Evolution==
The genus ''Camelops'' first appeared during the Late Pliocene period and became extinct at the end of the Pleistocene. Despite the fact that camels are presently associated with the deserts of Asia and Africa, the family ''Camelidae'', which comprises camels and llamas, originated in North America during the middle Eocene period, at least 44 million years ago.〔(【引用サイトリンク】title=Camelops )〕 The camel and horse families originated in the Americas and migrated into Asia via the Bering Strait. The skull of a ''Camelops'' was found above the Glenns Ferry Formation, in a thick layer of coarse gravel known as the Tauna Gravels. Above this layer of gravel is another layer of fine river channel sands, where the skull was found. This indicates that the ''Camelops'' is perhaps as young as 2 million years old, and perhaps even younger. This can be inferred because it is younger than the other fossils found at the Hagerman Fossil Beds National Monument.
During the late Oligocene and early Miocene periods, camels underwent swift evolutionary change, resulting in several genera with different anatomical structures, ranging from those with short limbs, those with gazelle-like bodies, and giraffe-like camels with long legs and long necks. This rich diversity decreased until only a few species, such as ''Camelops hesternus'', remained in North America, before going extinct entirely around 11,000 years ago.〔 ''Camelops extinction was part of a larger North American die-off in which native horses, camelids and mastodons also died out. Possibilities for extinction include global climate change and hunting pressure from the arrival of the Clovis people, who were prolific hunters with distinct fluted stone tools which allowed for a spear to be attached to the stone tool.〔〔 This megafaunal extinction coincided roughly with the appearance of the big game hunting Clovis culture, and biochemical analyses have shown that Clovis tools were used in butchering camels.
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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