Heminautilus

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
Temporal range: Aptian
~
Scientific classification
Kingdom:
Phylum:
Class:
Subclass:
Order:
Superfamily:
Family:
Cenoceratidae
Genus:
Heminautilus

Spath 1927
Species
  • H. boselliorum
  • H. etheringtoni
  • H. japonicus
  • H. lallierianus
  • H. rangei
  • H. sanctaecrucis
  • H. saxbii
  • H. stantoni
  • H. tejeriensis
  • H. tyosiensis
  • H. verneuilli

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

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

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

References

  1. Kummel, 1964
  2. Heminautilus at Fossilworks.org
  3. Baudouin et al., 2016, p.87
  4. Baudouin, 2016, p.76
  5. Baudouin, 2016, p.66
  6. Baudouin, 2016, p.72

Bibliography

  • 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. {{cite book}}: |work= ignored (help)

Further reading


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