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|regnum = Animalia |phylum = Mollusca |classis = Cephalopoda |subclassis = Ammonoidea |ordo = Ammonitida |subordo = Ammonitina |superfamilia = Stephanocerataceae |familia = Thomboceratidae |genus = ''Ermoceras'' }} ''Ermoceras'' is a thomboceratid ammonite from the Middle Jurassic ( u Baj) of central Arabia, Sinai, and Algeria with strong primary and secondary ribs and a single row of lateral tubercles; described as having a deep ventral groove 〔Arkell et al 1957, Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Ammonoidea〕 ''Telermoceras'', with low, depressed whorls, and ''Kosmermoceras'' with high,compressed whorls are considered subgenera of ''Ermoceras'' 〔 Both are from the same time and region. ''Telermoceras'' has coarse secondary ribs and a deep umbilicus surrounded by large tubercles or spines. ''Kosmermoceras''has fine sharp to coarse ribbing and a flattish venter ''Ermoceras'' ''s.l.'' is derived from ''Arkelloceras''. Westermann (1965)〔Westernamm,G. E. G. 1965.Septal and Sutural Patterns in Evolution and Taxonomy of Thamboceratidae and Clydoniceratidae (M Jurassic Ammonitina).Jour of Paleontology 39(5)864-874, Sept〕 tentatively placed ''Ermoceras'' in the Thamboceratidae, based on sutural morphology, removing it from the Stephanoceratidae where it was previously included. ==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「Ermoceras」の詳細全文を読む スポンサード リンク
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