Acrocanitidae is one of seven families of the Prionocerataceae families, 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. References Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, Volume 243, Number 2, February 2007, pp. 127–148(22) The Paleobiology Database accessed on 10/01/07 Goniatitida families Prionocerataceae