Acompsoceras

Acompsoceras is an extinct genus of cephalopod belonging to the Ammonite subclass. It grew to a large size compared to most ammonites. Its shell reached in diameter when the animal reached adulthood. "Acompsoceras" appears in the fossil record during the early portion of the Cretaceous Cenomanian stage and goes extinct around the middle of that same stage.
Species.
"Acompsoceras" is in the same family as "Acanthoceras", the Acanthoceratidae, and contains several species:
Distribution.
Fossils of "Acompsoceras" have been found in Brazil, Colombia (Hiló Formation), Germany, Madagascar, Nigeria, the United Kingdom and Texas.