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''"Crocodylus" megarhinus'' is an extinct species of crocodile from the Eocene of Egypt. A partial skull was found by British paleontologist Charles William Andrews in the Fayum Depression. Andrews named ''Crocodylus megarhinus'' in 1905 on the basis of the holotype skull. A complete skull was also uncovered from Egypt in 1907 but was not recognized as ''"C." megarhinus'' until 1927. ''"C." megarhinus'' shares many features with living crocodiles like the Nile crocodile (''C. niloticus''), including a robust triangular skull that is shorter than most other crocodiles. Similarities are also seen in the teeth of the two species. Like living crocodiles, ''"C." megarhinus'' has several constricted areas along the upper jaw that provide spaces for the teeth of the lower jaw when the mouth is closed. The proportions of ''"C." megarhinus'' and ''C. niloticus'' are so similar that American paleontologist Charles C. Mook considered it "very probable that ''C. megarhinus'' is a direct ancestor of ''C. niloticus''."〔 A second Fayum crocodilian, ''"Crocodylus" articeps'', was named alongside ''"C." megarhinus''. Andrews distinguished ''"C." articeps'' from ''"C." megarhinus'' on the basis of its narrower snout, which is more similar to the Slender-snouted crocodile than the Nile crocodile. ''"C." articeps'' has recently been synonymized with ''"C." megarhinus'', and may represent a less mature form in the species' population. Although it has traditionally been described as a species of ''Crocodylus'', ''"C." megarhinus'' has been placed outside the genus in many recent phylogenetic analyses. A new genus has not yet been erected for the species. ''"C." megarhinus'' is usually found to be a basal crocodyline outside the genus but still more closely related to it than the false gharial or mekosuchines. Below is a cladogram modified from Puértolas ''et al.'' (2011) showing its phylogenetic placement among crocodiles: }} }} }} }} }} }} }} ==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「Crocodylus megarhinus」の詳細全文を読む スポンサード リンク
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