Spitidiscus

Spitidiscus is a genus of ammonites placed in the family Holcodiscidae.
Species.
List of species within "Spitidiscus":
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: