Dakeoceras
| Dakeoceras Temporal range: L Ordovician | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | Ellesmerocerida |
| Family: | Ellesmeroceratidae |
| Genus: | Dakeoceras Ulrich & Furnish, 1931 |
Dakeoceras is a simple cyrtoconic ellesmeroceratid genus of cephalopods in the fossil record. All known species come from the Lower Canadian epoch (Gasconadian) of North America.
The Dakeoceras shell is an endogastric cyrtocone with the siphuncle on the concave, ventral, side; moderately curved and expanded in the juvenile stages which become reduced in the adult.
Forms in which the cross section is broadened, with the venter becoming flattened, are separated as Paradakeoceras. Quebecoceras is also similar but for its circular cross section and more persistent rate of expansion and curvature. Levisoceras is more compressed, more strongly curved, and has a higher rate of expansion especially in the vertical plane.
references
- Flower, R.H. 1964. The Nautiloid Order Ellesmerocerida (Cephalopoda); Memoir 12, New Mexico Bureau of Mines and Mineral Resources, Socorro N.M.
- W. M. Furnish & Brian F. Glenister, 1964. Nautiloidia --Ellesmerocerida. Treatise on Invertebrate Paleontology, Part K. Geological Society of America, Teichert and Moore (eds).
This article is issued from Wikipedia - version of the Monday, September 14, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.