''Cardioceras'' is an extinct

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttle ...

genus belonging to the family Cardioceratidae. These fast-moving nektonic carnivores lived during the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

period, Oxfordian age.

Description

Shells of ''Cardioceras'' species can reach a diameter of . The shape is circular, with ribs and a prominent ridge along the dorsal edge.

Distribution

Fossils of species within this genus have been found in the

of France, Germany, Poland, Russia, the United Kingdom and Alaska.Ralph W. Imlay (1981). Late Jurassic Ammonites of Alaska
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References

Jurassic ammonites Ammonites of Europe Ammonitida genera Stephanoceratoidea {{ammonitina-stub