Paractinoceras
Appearance
Paractinoceras Temporal range: Middle Ordovician
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Cephalopoda |
Subclass: | Nautiloidea |
Order: | †Actinocerida |
Family: | †Actinoceratidae |
Genus: | †Paractinoceras Hyatt in Zittle, 1900 |
Paractinoceras is a genus of long, straight, and slender actinocerid nautiloid with siphuncular segments in the early stages like those of Actinoceras, becoming narrower in the later stages of the chambered phragmocone like those in Ormoceras. As with Kochoceras and Floweroceras, Paractinoceras is considered a separate genus within the Actinoceratidae, distinct from Actinoceras.
References
[edit]- Flower R.H 1968, The First Great Expansion of the Actinoceroids, New Mexico Bureau of Mines and Mineral Resources Memoir 19 Part I, Socorro NM
- C. Teichert (1964). R.C. Moore (ed.). Part K, Mollusca 3. Treatise on Invertebrate Paleontology. Lawrence, Kansas: Geological Society of America and University of Kansas Press. p. K190–K216.