Echioceratidae is an extinct family of ammonites that lived during Sinemurian stage of Early Jurassic.[1]

Echioceratidae
Temporal range: Sinemurian, 196.5– 189.6 Ma [1]
Fossil shells of Echioceras raricostatum from Pierreclos (France), on display at Galerie de paléontologie et d'anatomie comparée in Paris
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Suborder: Ammonitina
Superfamily: Psiloceratoidea
Family: Echioceratidae
Buckman, 1913

Description

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Ammonites belonging to this family are characterised by serpenticone shells with a keel, which can be surrounded by grooves if a species is densely ribbed and compressed. The whorl section is either circular or has flat sides. Ribs are simple and strong with the exception of Leptechioceras which instead possessed a strongly compressed, smooth outer whorl. The initial ontogenical stage of these ammonites is typically smooth but very short. Tubercules are represented in a few genera within this group. [1]

Genera and subgenera

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Following genera are members of this family:[1]

Distribution

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Fossils of species within this family have been found in the Jurassic rocks of north Africa, South and North America, Europe and Asia.[2][1]

References

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  1. ^ a b c d e M. K. Howarth 2013. Treatise on Invertebrate Paleontology, Part L, Revised, Volume 3B, Chapter 4: Psiloceratoidea, Eoderoceratoidea, Hildoceratoidea.
  2. ^ The Paleobiology Database