Castelloceras is an extinct genus of actively mobile carnivorous cephalopod of the family Baltoceratidae that lived in what would be Europe during the Ordovician from 468—443.7 mya, existing for approximately .PaleoBiology Database: Castelloceras, basic info
Taxonomy Castelloceras was named by Evans (2005). Its type is Castelloceras arennigense. It was assigned to Baltoceratidae by Evans (2005).D. H. Evans. 2005. The Lower and Middle Ordovician cephalopod faunas of England and Wales. Monograph of the Palaeontographical Society 623:1-81
Sources
Fossils (Smithsonian Handbooks) by David Ward