Wikipedia
Ataxioceras
Ataxioceras is an extinct Ammonite cephalopod genus confined to the Upper Jurassic of Europe, included in the superfamily Perisphinctaceae.
Previously Ataxioceras was assigned to the Perisphinctidae but has now been placed in the Ataxioceratidae for which it is the type genus.
These fast-moving nektonic carnivores lived during the Jurassic period, from 161.2 to 150.8 Ma.