Calycoceras is an extinct genus of cephalopods belonging to the subclass Ammonoidea and family Acanthoceratidae that lived during the Cenomanian stage of the Late Cretaceous, 100-94 Mya.Sepkoski, Jack Sepkoski's Online Genus Database – Cephalopodes Their shells had ornate ribs.Ammonites
Species C. algeriense Kennedy & Gale, 2017 C. annulatum Collignon, 1964 C. asiaticum (Jimbo, 1894)William James Kennedy, Herbert Christian Klinger (2010) Cretaceous faunas from Zululand and Natal, South Africa. The ammonite subfamily Acanthoceratinae de Grossouvre, 1894 C. a. asiaticum (Jimbo, 1894) C. a. spinosum (Kossmat, 1897) C. besairieri Collignon, 1937 C. boreale Kennedy, Cobban & Landman, 1996 Global Names Index C. dromense (Thomel, 1972) AMNH C. cenomanense (d’Archiac, 1846) C. navicularis (Mantell, 1822) C. orientale Matsumoto, Saito & Fukada UMUT C. paucinodatum (Crick) Smithsonian Institutions C. tarrantenseThe Paleobiology Database
Distribution Calycoceras species may be found in the Cretaceous of Angola, Antarctica, Canada (British Columbia), France, Germany, Japan, Nigeria, Oman, Russia, the United Kingdom, United States (Alaska, Arizona, Kansas, New Mexico, South Dakota, Utah)
C. asiaticum may be found in the Cenomanian of Canada, Southern England, northern and southern France, Spain, Romania, Bulgaria, Tunisia, Madagascar, south India and Japan.Paleobiology Database
C. cenomanense may be found in the Cenomanian of United Kingdom, France and Madagascar. P. Moreau, I.H. Francis, W.J. Kennedy Cenomanian ammonites from northern aquitaine William James Kennedy, Ireneusz Walaszczyk, Andrew S. Gale, Krzysztof Dembicz, Tomasz Praszkier - Lower and Middle Cenomanian ammonites from the Morondava Basin, Madagascar W. J. Kennedy 1971. - Cenomanian Ammonites from Southern England. Special Papers in Palaeontology Number 8. v + 133 pp., 64 pls, 5 tables. The Palaeontological Association, London Sepkoski, Jack Sepkoski's Online Genus Database – Cephalopodes
Description Shells of Calycoceras asiaticum may reach a diameter of about . The larger phragmocones may reach in diameter. Coiling is moderately involute. All ribs show strong subspinose tubercles. C. asiaticum asiaticum and C. asiaticum spinosum are very similar, the latter has much more robust tuberculation.Ammonites
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