Heminautilus
Heminautilus Temporal range: Aptian ~ | |
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Genus: | Heminautilus Spath 1927 |
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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 Barremian and 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 they are 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
[edit]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. tejeriensis
- H. tyosiensis
- H. verneuilli
Distribution
[edit]Fossils of Heminautilus have been found in Bulgaria, Colombia (at Caballos Formation, Boyacá, Tolima and Une Formation),[3] Egypt,[4] France, Hungary,[5] Japan, Mexico, Spain, Switzerland, Tunisia,[6] the United Kingdom, the United States (Arkansas), Venezuela.[2]
See also
[edit]References
[edit]Bibliography
[edit]- Baudouin, Cyril; Delanoy, Gérard; Moreno Bedmar, Josep Antón; Pictet, Antoine; Vermeulen, Jean; Conte, Gabriel; Gonnet, Roland; Boselli, Patrick; Boselli, Marc (2016). "Revision of the Early Cretaceous genera Heminautilus SPATH, 1927, and Josanautilus MARTÍNEZ & GRAUGES, 2006 (Nautilida, Cenoceratidae)" (PDF). Carnets de Géologie. 16 (5): 61–212. doi:10.4267/2042/58977. Retrieved 2017-01-20.
- Kummel, B. (1964). Nautiloidea -Nautilida. Geological Society of America and University of Kansas Press.
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Further reading
[edit]- Sepkoski Jr., J.J. (2002). D.J. Jablonski & M.L. Foote (ed.). "A compendium of fossil marine animal genera". Bulletins of American Paleontology. 363: 1–560.