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

Description

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

Following genera are members of this family:[1]

Distribution

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

  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


Allikas: https://en.wikipedia.org/wiki/Echioceratidae
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