Manitoulinoceras

Manitoulinoceras
Temporal range: Late Ordovician
Scientific classification
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: Oncocerida
Family: Valcouroceratidae
Genus: Manitoulinoceras
Foeste, 1924


Manitoulinoceras is a Late Ordovician oncocerid nautilod cephalopod, 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 early part of 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

This article is issued from Wikipedia - version of the 4/12/2014. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.