Allocotoceras is an endocerid from the Lower Ordovician (upper Canadian) Karmberg Formation of Australia (Tasmania),[1] included in the Endoceratidae, based on small, straight or gently curved siphuncles.
| Allocotoceras Temporal range: Darriwilian
~ | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | †Endocerida |
| Family: | †Endoceratidae |
| Genus: | †Allocotoceras Teichert & Glenister 1953 |
Septal necks, according to Teichert, 1964, are holochoanitic, reaching to the previous septum. Endocones are described as having a dorsal wedge, or process, making the internal opening, or endosiphocone, semicircular in cross section. In this sense Allocotoceras seems to resemble the genus Najaceras.
References
edit- ^ Allocotoceras at Fossilworks.org
Further reading
edit- Corbett, K. D.; Banks, M. R. (1973). "Ordovician stratigraphy of the Florentine Synclinorium, southwest Tasmania". Papers and Proceedings of the Royal Society of Tasmania. 107: 207–238. doi:10.26749/rstpp.107.207. S2CID 126628381.
- Teichert, C. 1964. Endoceratoidea. Treatise on Invertebrate Paleontology, Part K. Endoceratoidea, Actinoceratoidea, Nautiloidea. Geological Soc. of America and Univ. Kansas Press