Cycloceras
| Cycloceras Temporal range: Ordovician-Permian | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | Orthocerida |
| Genus: | Cycloceras McCoy (1844) |
Cycloceras is an extinct nautiloid cephalopod genus from the Carboniferous of Western Europe, (Ireland and Scotland) of unknown affinity with the orthocerida (Sweet 1964 in) [1]
Taxonomy
Cycloceras was named by McCoy (1844 and assigned to the Michelinoceratida by Flower (1962)and to the Orthocerida by Sweet in Teichert et al. (1964);[2] Cycloceras is possibly a member of the Cycloceratidae and may be synonymous with Perigrammoceras Foerste
Morphology
The type species of Cycloceras, C. annularis, is based in an internal mold of a body chamber on which the position of the siphuncle is indiscernible (Sweet 1964,) Species referred to Cycloceras are annulated, subcylindrical orthocones with no longitudinal ornamentation . Fig 186, p K258 Teichert et al. (1964) shows Cycloceras as narrow, gently expanding, annulated othocone with a narrow subcentral siphuncle. Annuli (circular transverse bands or costae) are thick and close spaced, giving a corrugated appearance.
References
- ↑ C. Teichert et al 1964. Treatise on Invertebrate Paleontology K(3)Nautiloidea:1-519
- ↑ PaleoBiology Database:Cycloceras,basic info