羊角菊石

羊角菊石（學名：），又名公羊齒菊石，是生存於白堊紀的一屬菊石，生活在中等深度的大陸棚海域中。其化石分布於歐洲、非洲、亞洲和美洲。

特徵
羊角菊石的外殼盤捲得很鬆，外觀猶如盤曲的羊角，因而得名。其殼階互不相連。殼階的大小由內而外增長得很快。殼上飾有肋條，長有結節、較結實的粗肋條之間有二至三個無結節且較為纖細的肋條隔著。腹是圓形的。

物種
的Crioceratites nolani化石]]
*Crioceras (Acanthodiscus)
*Crioceras dilatatum
*Crioceras munieri
*Crioceras obliquatum
*Crioceras simplex
*Crioceratites (Crioceratites)
*Crioceratites (Emericiceras)
*Crioceratites andersoni
*Crioceratites barrabei
*Crioceratites bituberculatus
*Crioceratites coniferus
*Crioceratites duvalii
*Crioceratites emerici
*Crioceratites heterocostatus
*Crioceratites krenkeli
*Crioceratites latus
*Crioceratites leivaensis
*Crioceratites loryi
*Crioceratites panescorsii
*Crioceratites portarum
*Crioceratites tehamaensis
*Crioceratites tener
*Crioceratites yollabollium

參考文獻
外部連結

• [http://paleodb.org/cgi-bin/bridge.pl?action=basicTaxonInfo&taxon_no=14733 Crioceratites] in the Paleobiology Database

延伸閱讀

• Simon & Schuster's Guide To Fossils (Nature Guide Series) by Paolo Arduini
• , Part L, Ammonoidea,--Ancyloceratiaceae; Geological Society of America 1957, reprinted 1990.

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