Wikipedia
Acutimitoceras
Acutimitoceras is a genus belonging to the Acutimitoceratinae subfamily of the Prionoceratidae family, a member of the Goniatitida order. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.