| 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.
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