Caractères ornementaux, disparité et diversité chez les Ammonitina : exemple des Kosmoceratinae (Stephanoceratoidea), Callovien moyen et supérieur (Jurassique moyen, Bassin parisien)


fr Comptes Rendus Palevol 10 (2-3) - Pages 155-170

Published on 30 April 2011

This article is a part of the thematic issue The species concept in palaeontology: Ontogeny, variability, evolution

Ornamental characters, disparity and diversity within Ammonitina: Example of the Kosmoceratinae (Stephanoceratoidea), Middle to Upper Callovian (Middle Jurassic, Paris Basin)

The Kosmoceratinae Tintant, 1963, consist of a subfamily of Jurassic Ammonitina of boreal origin, of which most species are highly polymorphic. Because of their rapid evolution and diversification they represent a major group for establishing Middle to Upper Callovian biostratigraphy. During its history, this taxon records an extreme and sudden diversification across the boundary between the substages. This step took place according to two distinct modes: 1- a rather progressive although rapid increase in both diversity and disparity of the dominant groups during most of the Middle Callovian; 2- a sudden two steps renewal of ornamental patterns giving rise to a quick reorientation of both disparity and diversity. This double event is well recorded and synchronous at the European scale.


Kosmoceras , Ammonitina, Morphology, Callovian, Jurassic, Paris Basin, France

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