Dakeoceras

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, all known species of which come from the Lower Canadian (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).