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|regnum = Animalia |phylum = Mollusca |classis = Cephalopoda |subclassis = Ammonoidea |ordo = Ammonitida |superfamilia = Stephanocerataceae |familia = Cardioceratidae |genus = ''Arctocephalites'' |genus_authority = Spath (1928) |subdivision_ranks = |subdivision = }} ''Arctocephalites'' is an extinct ammonitic cephalopod genus from the Middle Jurassic with a wide northern distribution belonging to the stephanoceratacean family, Cardioceratidae.〔Arkell et at, 1957, Mesozoic Ammonoidea , Treatise on Invertebrate Paleontology, Part L, Mollusca 4, R.C. Moore, ed. p.L301〕 The inner whorls of the ''Arctocephalites'' shell are sharply ribbed but change abruptly to smooth. The such, as characteristic of the family, is complex with large first lateral lobe and well-developed umbilical lobe.〔 ''Arctocephalites'' has been found in Bathonian age sediments at Cook Inlet, Alaska, in western Montana,and in the North Sea at paleolatitudes ranging from about 30deg N to 50deg N.〔( Paleobiology Database -Arctocephalites ) 12/14/09〕 It has been found in equivalent age sediments in the Volga and Pechora river basin in Russia 〔( Correlation of Upper Bajocian-Bathonian Zones in Siberia )...S.V. Meledina et al 2009〕 as well as in Greenland, FanzJoseph Land, NovayZemlya, and eastern Siberia.〔 ==''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「Arctocephalites」の詳細全文を読む スポンサード リンク
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