References
- Walter C Sweet 1964. Nautiloidea-Orthocerida; Treatise on Invertebrate Paleontology, Part K. Geol Soc of America and Univ. Kansas Press.
 | This prehistoric cephalopod-related article is a stub. You can help Wikipedia by expanding it. |
| Sigmocycloceras Temporal range: M. Ordovician | |
|---|---|
| Scientific classification | |
| Kingdom: | |
| Phylum: | |
| Class: | |
| Subclass: | |
| Order: | |
| Family: | |
| Genus: | Sigmocycloceras Kobayashi, 1934 |
Sigmocycloceras is a nautiloid cephalopod discovered in the Middle Ordovician of Korea, said to be similar to Sactorthoceras , and included in the Sactorthoceratidae, but unique in being longitudinally sigmoid and sculpted with transverse annuli.
| | This prehistoric cephalopod-related article is a stub. You can help Wikipedia by expanding it. |