Heminautilus
| Heminautilus | |
|---|---|
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | Nautiloidea |
| Order: | Nautilida |
| Superfamily: | Nautilaceae |
| Family: | Cenoceratidae |
| Genus: | Heminautilus Spath 1927 |
| Species | |
| |
Heminautilus is an extinct genus of nautiloids from the nautilacean family Cenoceratidae that lived during the Early Cretaceous.[1] Fossils of Heminautilus have been registered in rocks of Aptian age.[2] 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.[1]
Species
The following species of Heminautilus have been described:[2]
- H. boselliorum
- H. etheringtoni
- H. japonicus
- H. lallierianus
- H. rangei
- H. sanctaecrucis
- H. saxbii
- H. stantoni
- H. tyosiensis
Distribution
Fossils of Heminautilus have been found in Bulgaria, Colombia (Caballos Formation, Tolima and Une Formation, Boyacá),[3] Egypt,[4] France, Hungary,[5] Japan, Mexico, Spain, Switzerland, Tunesia,[6] the United Kingdom, the United States (Arkansas), Venezuela.[2]
See also
References
Bibliography
- Badouin, Cyril; Delanoy, Gérard; Moreno Bedmar, Josep Antón; Pictet, Antoine; Vermeulen, Jean; Conte, Gabriel; Gonnet, Roland; Boselli, Patrick; Bonelli, Marc (2016). "Revision of the Early Cretaceous genera Heminautilus SPATH, 1927, and Josanautilus MARTÍNEZ & GRAUGES, 2006 (Nautilida, Cenoceratidae)" (PDF). Carnets de Géologie. 16: 61–212. Retrieved 2017-01-20.
- Kummel, B. (1964). Nautiloidea -Nautilida. Treatise on Invertebrate Paleontology. Geological Society of America and University of Kansas Press.
Further reading
- Sepkoski Jr., J.J. (2002). D.J. Jablonski & M.L. Foote, ed. A compendium of fossil marine animal genera. Bulletins of American Paleontology. 363. pp. 1–560.