Zittelloceras
From Wikipedia, the free encyclopedia
| Zittelloceras Temporal range: M-U Ordovician | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | †Oncocerida |
| Family: | †Oncoceratidae |
| Genus: | †Zittelloceras Hyatt (1884) |
Zittelloceras is an extinct genus of nautiloids 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 slightly 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)
