Manitoulinoceras

Manitoulinoceras Temporal range:
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Nautiloidea
Order:	†Oncocerida
Family:	†Valcouroceratidae
Genus:	†Manitoulinoceras Foeste, 1924

Manitoulinoceras is a genus of Late Ordovician oncocerid nautiloid cephalopods, found in North America (Kentucky, Ohio, Indiana, and Ontario). The shell is cyrtoconic, exogastric, more strongly curved than in Kindleoceras. The cross-section is somewhat wider than high, with a somewhat flattened upper side, known as the dorsum. Actinosiphonate deposits in the siphuncle are confined to the early part of the phragmocone.

Staufferoceras, a valcuouroceratid from the Middle and Upper Ordovician of Minnesota and Ohio named by Foeste, 1932, is much like Manitoulinoceras but with a living chamber that is swollen in the middle, narrowing toward the aperture.

References

• Walter C Sweet, 1964 Nautiloidea-Oncocerida. Treatise on Invertebrate Paleontology Part K Mollusca 3. Geological Society of America and University of Kansas Press.