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''Turrilites'' is a helically coiled ammonoid cephalopod from the lower part of the Upper Cretaceous (Cenomanian and Turonian); generally included in the Ancyloceratina. Previously (Arkell, 1957) it was included in the ammonoid suborder, Lytoceratina. The shell of ''Turrilites'' is tightly wound in a high trochospiral, with an acute angle at the apex. Ribs are weak to strong and may have 3 or 4 rows of equal numbers of tubercles. Thought to be derived from ''Mariella''. Includes three subgenera. ==Subgenera and species== ''Turrilites'' has three subgenera. * ''Turrilites (Turrilites)'' Lamarck 1801 * * ''Turrilites acutus'' Passy 1832 * * ''Turrilites costatus'' Lamarck 1801 * * ''Turrilites scheuchzerianus '' Bosc 1801 * ''Turrilites (Euturrilites) '' Breistroffer 1953 * ''Turrilites (Mesoturrilites) Subgenus ''Turrilites'' has weak ribs and strong tubercles. Subgenus ''Euturrilites'' has strong ribs, commonly depressed in middle, especially on early whorls, and no tubercles. Subgenus ''Mesoturrilites'' has almost no ribs and clavate tubercles that tend to form spiral ridges. 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「Turrilites」の詳細全文を読む スポンサード リンク
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