Echioceratidae is an extinct family of ammonites that lived during Sinemurian stage of Early Jurassic.[1]
| Echioceratidae Temporal range: Sinemurian, [1] | |
|---|---|
 | |
| Fossil shells of Echioceras raricostatum from Pierreclos (France), on display at Galerie de paléontologie et d'anatomie comparée in Paris | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Subclass: | †Ammonoidea |
| Order: | †Ammonitida |
| Suborder: | †Ammonitina |
| Superfamily: | †Psiloceratoidea |
| Family: | †Echioceratidae Buckman, 1913 |
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]
- Palaeoechioceras Spath, 1929
- Gagaticeras Buckman, 1913
- Plesechioceras Trueman and Williams, 1925
- Orthechioceras Trueman and Williams, 1925
- Echioceras Bayle, 1878
- Paltechioceras Buckman, 1924
- Leptechioceras Buckman, 1923
- L. (Leptechioceras)
- L. (Neomicroceras) Donovan, 1966
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]
