''Skirroceras macrum'' is a Stephanoceratacean (ammonite) species belonging to the family

Stephanoceratidae Stephanoceratidae is a family of planulate and coronate ammonites within the Stephanoceratoidea.Arkell, Kummel, and Wright, 1957. Mesozoic Ammonoidea; Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Shells are evolute so that all whorl ...

. These fast-moving nektonic carnivores lived during the Jurassic period, in the Bajocian age.Sepkoski, Jac
Sepkoski's Online Genus Database – Cephalopoda
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Description

''Skirroceras macrum'' has an evolute shell reaching about of diameter. These ammonites are heavily ribbed, with characteristic nodes.

Distribution

Fossils of ''Skirroceras macrum'' are found in the Middle Jurassic Bajocian age marine strata of England and France.Discover Yale
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References

* P. E. BARTOK, O. RENZ and G.E.G. WESTERMAN
The Siquisique ophiolites, Northern Lara State, Venezuela: A discussion on their Middle Jurassic ammonites and tectonic implications

External links

UK Fossils
Jurassic ammonites Stephanoceratoidea {{ammonitina-stub