Cardioceras is an extinct ammonite genus belonging to the family Cardioceratidae. These fast-moving nektonic carnivores lived during the Jurassic period, Oxfordian age.Mikko's Phylogeny Archive
Description Shells of Cardioceras species can reach a diameter of .Cardioceras.ru The shape is circular, with ribs and a prominent ridge along the dorsal edge.Encyclopædia Britannica
Distribution Fossils of species within this genus have been found in the Jurassic of France, Germany, Poland, Russia, the United Kingdom and Alaska.Ralph W. Imlay (1981). Late Jurassic Ammonites of Alaska
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