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Megapedetes
''Megapedetes'' is a genus of fossil rodents related to the springhare and other species of the genus ''Pedetes'', with which it forms the family Pedetidae. At least four species are known, which ranged through Africa, southwestern Asia, and southeastern Europe from the Miocene to the Pliocene. The genus was larger than ''Pedetes''.
Species of ''Megapedetes'' were larger, relatively low-crowned (brachydont) pedetids with short, mostly fused roots under their teeth. There was no gutter surrounding the incisive foramina (openings in the front part of the palate). The bones are more robustly built than in ''Pedetes'' and in another fossil relative of the springhares, ''Parapedetes''.〔Mein and Senut, 2003, p. 161〕 Unlike in ''Pedetes'', the first metatarsal (a foot bone) is present.〔Mein and Senut, 2003, p. 162〕 It may have fed on less rough vegetation than ''Pedetes'' does.〔Winkler, 1992, p. 239〕
In Namibia, two species are known from the early middle Miocene〔Mein and Senut, 2003, p. 163〕 of Arrisdrift—''M. gariepensis'' and ''M. pickfordi''. An isolated phalanx from a slightly older site, Auchas Mine, cannot be reliably identified to species level,〔 but may be ''M. gariepensis''.〔Mein and Senut, 2003, p. 167〕 ''Megapedetes'' and other pedetids are reasonably common in the Miocene of East Africa.〔 ''M. pentadactylus'', the type species of the genus, occurs at Songhor, Rusinga, and Bukwa;〔Mein and Senut, 2003, p. 169; Winkler, 1992, p. 239; Walker, 1969, p. 592〕 a species that may be close to ''M. gariepensis'' is known from Kirimun, Fort Ternan, and Maboko; a pedetid from Kipsaraman resembles ''M. pickfordi'', but is more low-crowned; and other pedetids may occur in other East African sites.〔Mein and Senut, 2003, p. 169; Winkler, 1992, p. 239〕 A species of ''Megapedetes'', perhaps ''M. pentadactylus'', is known from Saudi Arabia in sediments about 16 million years old.〔 In the early Miocene of Israel, a yet undescribed pedetid close to ''Megapedetes'' is found.〔Wood and Goldsmith, 1998, p. 87A〕 Species of ''Megapedetes'' are also known from the Miocene and Pliocene of North Africa.〔 Another species, ''Megapedetes aegaeus'', occurs at Bayraktepe in Turkey〔Sen, 1977, p. 984〕 and the genus has also been found on the Greek island of Chios.〔
Among the two Arrisdrift species, ''M. gariepensis'' is about 15% smaller than the East African ''M. pentadactylus'' and more adapted to jumping and has less robust incisors, more high-crowned (hypsodont) cheekteeth.〔 The second species, ''M. pickfordi'', is even smaller and more hypsodont.〔Mein and Senut, 2003, p. 166〕 ''M. aegaeus'' and ''M. pentadactylus'' differ in details of the crowns of the cheekteeth.〔
==References==
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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