Kingdom Animalia Family Holcodiscidae Rank Genus | Class Cephalopoda Phylum Mollusca Order Ammonitida | |
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Similar Tissotia, Virgatites, Tragophylloceras, Reineckeia, Zigzagiceras | ||
Spitidiscus is a genus of ammonites placed in the family Holcodiscidae.
Contents
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.
Geologic Time Scale
The first appearance of the species Spitidiscus hugii or Spitidiscus vandeckii are proposed to be the marker for the beginning of the Barremian.
Distribution
Spitiduscus has been found in the Lower Cretaceous of Europe (Czechoslovakia, France, Italy, Portugal, Spain, Russia), as well as of Morocco, Argentina, Colombia and Mexico. The type species S. rotulia is from the Hauterivian of England.