Spitidiscus is a genus of ammonites placed in the family Holcodiscidae. with and (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.
Species List of species within Spitidiscus: Spitidiscus hugii Spitidiscus kilapiae Rawson and Aguirre-Urreta, 2012 - Argentina Spitidiscus oregonensis Imlay, 1960 - Oregon Spitidiscus riccardii Leanza, and Wiedmann, 1992 - Argentina Spitidiscus rotulia - England Spitidiscus simitiensis Haas, 1960 - Colombia Spitidiscus vandeckii (d'Orbigny, 1847)
Description 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.
Biostratigraphic significance The first appearance of the species Spitidiscus hugii or Spitidiscus vandeckii are proposed to be the marker for the beginning of the Barremian.
Distribution Spitidiscus has been found in: Agrio Formation, Argentina Magdalena Valley, Simití and Cáqueza, Colombia Kaliste Formation, Czech Republic France Gagra, Georgia, Caucasus Maiolica Formation, Italy Subbetics, Spain Foggy Creek, Oregon Bulgaria Portugal Russia Morocco Mexico
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