Spitidiscus is a genus of ammonites placed in the family Holcodiscidae.[1][2]

Spitidiscus
Temporal range: Hauterivian-Barremian
~130–125 Ma
Fossil shell of Spitidiscus species from Alpes-de-Haute-Provence, on display at Galerie de paléontologie et d'anatomie comparée in Paris
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Family: Holcodiscidae
Genus: Spitidiscus
Kilian, 1910
Spitidiscus seunesi (Kilian) Barremian, Brestak, Cr1 426X1 (Coll. St. Breskovski) at the Sofia University Museum of Paleontology and Historical Geology

Species

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List of species within Spitidiscus:[3]

  • Spitidiscus hugii[citation needed]
  • Spitidiscus kilapiae Rawson and Aguirre-Urreta, 2012 - Argentina
  • Spitidiscus oregonensis Imlay, 1960 - Oregon
  • Spitidiscus riccardii Leanza, and Wiedmann, 1992 - Argentina
  • Spitidiscus rotulia - England[citation needed]
  • Spitidiscus simitiensis Haas, 1960 - Colombia
  • Spitidiscus vandeckii (d'Orbigny, 1847)

Description

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Member species have a rather evolute shell in which the whorl section is more or less circular, venter broadly rounded and dorsum fairly deeply impressed. Close, fine low, single or rarely branching ribs are interspersed by frequent straight or slightly sinuous, moderately deep but wide constrictions. The type species S. rotulia is from the Hauterivian of England.[citation needed]

Biostratigraphic significance

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The first appearance of the species Spitidiscus hugii or Spitidiscus vandeckii are proposed to be the marker for the beginning of the Barremian.[4]

Distribution

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Spitidiscus has been found in:[3]

References

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  1. ^ Wright, C. W. with Callomon, J.H. and Howarth, M.K. (1996), Mollusca 4 Revised , Cretaceous Ammonoidea, vol. 4, in Treatise on Invertebrate Paleontology, Part L (Roger L. Kaesler et al. eds.), Boulder, Colorado: The Geological Society of America & Lawrence, Kansas: University of Kansas Press, at 69.
  2. ^ "Spitidiscus". Sepkoski's Online Genus Database – Cephalopoda.
  3. ^ a b "Spitidiscus". Fossilworks.
  4. ^ "GSSP Table - Mesozoic Era". Geologic Time Scale Foundation. Retrieved 15 January 2014.

Bibliography

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