Lytoceratidae, NEUMAYR, 1875


Fauna

Lytoceratidae

Pairs

Pseudoperisphinctidae

Parkinsoniidae

Clydoniceratidae

Morphoceratidae

Phlycticeratidae

Sphaeroceratidae

Oppeliidae

Lissoceratidae

Phylloceratidae

Family Lytoceratidae

It gathers together ammonites with circular, oval or subquadratic section and episodical constrictions. They are characterized by a fine and dense costulation and their venter is sometimes keeled. Their stratigraphic distribution spreads out from the Sinemurian up to the Cretaceous. However, it seems to be very rare in the Jurassic layers of the Cher and Nièvre.

Genus Nannolytoceras

It is rather uncommon in the Bathonian deposits of southern Paris Basin, on the contrary to southern France. Only one species has been recognized : Nannolytoceras tripartitum (Stur.). It is an evolute ammonite with several deep constrictions.

We are seeking .....
Nannolytoceras tripartitum ( Stur.)