{{Short description|Genus of molluscs (fossil)}} {{Automatic taxobox | fossil_range = Cretaceous | image = Gasteropods - Ammonites - Calycoceras (Newboldiceras) spinosa.JPG | image_caption = ''Calycoceras asiaticum spinosum'', Late Cretaceous (Cenomanian) from Madagascar, abt. 94 Mya | taxon = Calycoceras | authority = Hyatt, 1900 | subdivision_ranks = Species | subdivision = *See text | synonyms = * ''Newboldiceras'' }}
'''''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.<ref>Sepkoski, Jack [http://strata.geology.wisc.edu/jack/showgenera.php?taxon=183&rank=phylum Sepkoski's Online Genus Database – Cephalopodes]</ref> Their shells had ornate ribs.<ref>[http://www.ammonites.fr/Fiches/0829.htm Ammonites]</ref>
==Species== *''C. algeriense'' <small>Kennedy & Gale, 2017</small> *''C. annulatum'' <small>Collignon, 1964</small> *''C. asiaticum'' <small>(Jimbo, 1894)</small><ref name=fa>William James Kennedy, Herbert Christian Klinger (2010) [http://www.scielo.org.za/pdf/anh/v6/01.pdf Cretaceous faunas from Zululand and Natal, South Africa. The ammonite subfamily Acanthoceratinae de Grossouvre, 1894]</ref> **''C. a. asiaticum'' <small>(Jimbo, 1894)</small><ref name=fa/> **''C. a. spinosum'' <small>(Kossmat, 1897)</small><ref name=fa/> *''C. besairieri'' <small>Collignon, 1937</small> *''C. boreale'' <small>Kennedy, Cobban & Landman, 1996</small> <ref>[http://gni.globalnames.org/data_sources/6?page=1590&search_term=ns%3ACAL* Global Names Index]</ref> *''C. dromense'' <small>(Thomel, 1972) </small> <ref>[http://digitallibrary.amnh.org/dspace/bitstream/handle/2246/3621/n3161.pdf?sequence=1 AMNH]</ref> *''C. cenomanense'' <small>(d’Archiac, 1846) </small> *''C. navicularis'' <small>(Mantell, 1822)</small> *''C. orientale'' <small>Matsumoto, Saito & Fukada</small> <ref>[http://umdb.um.u-tokyo.ac.jp/DKoseibu/specimens/en/05657_.html UMUT]</ref> *''C. paucinodatum'' <small>(Crick)</small> <ref>[http://collections.si.edu/search/record/nmnhpaleobiology_3183458 Smithsonian Institutions]</ref> *''C. tarrantense''<ref name=fc>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=14666 The Paleobiology Database]</ref>
==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) <ref name=fa/>
''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.<ref name=fa/><ref name=fb>[https://paleobiodb.org/classic/checkTaxonInfo?taxon_no=130532 Paleobiology Database]</ref>
''C. cenomanense'' may be found in the Cenomanian of United Kingdom, France and Madagascar.<ref> P. Moreau, I.H. Francis, W.J. Kennedy [https://www.researchgate.net/publication/222807311_Cenomanian_ammonites_from_northern_aquitaine Cenomanian ammonites from northern aquitaine] </ref><ref> William James Kennedy, Ireneusz Walaszczyk, Andrew S. Gale, Krzysztof Dembicz, Tomasz Praszkier - Lower and Middle Cenomanian ammonites from the Morondava Basin, Madagascar</ref><ref> 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 </ref><ref> Sepkoski, Jack [http://strata.geology.wisc.edu/jack/showgenera.php?taxon=183&rank=phylum Sepkoski's Online Genus Database – Cephalopodes] </ref>
[[File:Calycoceras orientale.jpg|thumb|240px|right|''Calycoceras orientale'', Late Cretaceous from Japan.]]
==Description== Shells of ''Calycoceras asiaticum'' may reach a diameter of about {{convert|20|cm}}. The larger phragmocones may reach {{convert|59|-|72|mm}} 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.<ref name=fa/><ref>[http://www.ammonites.fr/Fiches/0529.htm Ammonites]</ref>
==References== {{Reflist}}
{{Taxonbar|from=Q5024617}}
Category:Acanthoceratidae Category:Ammonitida genera Category:Cretaceous ammonites Category:Late Cretaceous ammonites of North America Category:Late Cretaceous cephalopods of North America Category:Late Cretaceous animals of Africa Category:Cenomanian life