Heminautilus

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Heminautilus
Temporal range: Aptian
~125–112 Ma
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Nautiloidea
Order: Nautilida
Superfamily: Nautilaceae
Family: Cenoceratidae
Genus: Heminautilus
Spath 1927
Species
  • H. boselliorum
  • H. etheringtoni
  • H. japonicus
  • H. lallierianus
  • H. rangei
  • H. sanctaecrucis
  • H. saxbii
  • H. stantoni
  • H. tyosiensis

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[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. tyosiensis

Distribution[edit]

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[edit]

References[edit]

  1. ^ a b Kummel, 1964
  2. ^ a b c Heminautilus at Fossilworks.org
  3. ^ Badouin et al., 2016, p.87
  4. ^ Badouin, 2016, p.76
  5. ^ Badouin, 2016, p.66
  6. ^ Badouin, 2016, p.72

Bibliography[edit]

Further reading[edit]