Spitidiscus

Spitidiscus is a genus of ammonites placed in the family Holcodiscidae.

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