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The genus ''Phenacomys'' is a group of North American voles. The genus name comes from the Greek for "imposter mouse." These animals live in forested, alpine and tundra areas, which often include plants of the heath family. They are small rodents with long fur and short ears, legs and tails. They eat green plants, seeds and berries in summer and bark and buds of shrubs at other times. Predators include mustelids, owls and hawks. Some sources include the tree voles, genus ''Arborimus'', in this genus. At one time, the two species of heather vole were considered to be a single species. The complete list of living species is: *Western heather vole (''Phenacomys intermedius'') *Eastern heather vole (''Phenacomys ungava'') Unusual features in the teeth of ''Phenacomys'' voles suggest that the genus may have arisen relatively early within the evolutionary history of voles, probably in early Pliocene Beringia, from an Asian ancestor. The earliest American fossils date from about 1.5 million years ago, and were discovered in present day Idaho. Similarly aged fossils belonging to two extinct species, ''P. gryci'' and ''P. deeringensis'', have been discovered in Yakutia. During the Ice Ages of the Pleistocene, ''Phenacomys'' voles lived as far south as Arkansas.〔 ==References== 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「Heather vole」の詳細全文を読む スポンサード リンク
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