Kingdom Animalia Class Cephalopoda Order Oncocerida Rank Genus | Phylum Mollusca Subclass Nautiloidea Family Oncoceratidae | |
Zittelloceras is an extinct genus of nauiloids from the order Oncocerida which are among a large group of once diverse and numerous shelled cephalopods, now represented by only a handful of species.
Zittleoceras, which is included in the family Oncoceratidae, is characterized by subcircular or sightly depressed cyrtoconic shells with ventral, suborthochoanitic empty siphuncles; the shell surface typically with crenulated transverse frills or distinct noncrenulated annulations. Zittleoceras has been found in middle and upper Ordovician sediments in North America and Scotland. (Sweet, 1964)
References
Zittelloceras Wikipedia(Text) CC BY-SA