Heminautilus
| Heminautilus Temporal range: L Cretaceous | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | Nautilida |
| Superfamily: | Nautilaceae |
| Family: | Cymatoceratidae |
| Genus: | Heminautilus Spath (1927) |
Heminautilus is an extinct nautiloid genus from the nautilacean family Cymatoceratidae that lived during the early Cretaceous (Kummel 1964). Nautiloids are a subclass of shelled cephalopods that were once diverse and numerous but are now represented by only a handful of species.
Heminautilus has a discoidal compressed involute shell with flanks converging on a narrow flattened outer margin, the venter. Whorls are higher than wide. The suture is sinuous with a ventral lobe, subtriangular saddles on the ventral shoulders, broad lateral lobes, and narrow rounded saddles on the umbilical shoulders. The siphuncle is subcentral (Kummel 1964).
See also
- List of nautiloids
References
- Kummel,B. 1964. Nautiloidea -Nautilida, in the Treatise on Invertebrate Paleontology, Geological Society of America and University of Kansas Press.
- Sepkoski, J.J. Jr. 2002. A compendium of fossil marine animal genera. D.J. Jablonski & M.L. Foote (eds.). Bulletins of American Paleontology 363: 1–560. Sepkoski's Online Genus Database (CEPHALOPODA)