*** Welcome to piglix ***

Stephanoceratidae

Stephanoceratidae
Temporal range: Middle Jurassic–Upper Jurassic
Stephanoceratidae - Stephanoceras blagdeni.JPG
Stephanoceras blagdeni from Mid Jurassic - Germany
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Superfamily: Stephanocerataceae
Family: Stephanoceratidae

Stephanoceratidae is a family of planulate and coronate ammonites within the Stephanocerataceae. Shells are evolute so that all whorls are exposed and have strong ribbing that bifurcates, that is splits in two, on the flanks. Many have tubercles at the point of bifurcation. Whorl sections are generally subequant; the outer rim, or venter, commonly rounded.

The Stephanoceratidae are derived from the Otoitidae. Their fossils are found in upper Middle- and lower Upper Jurassic sediments.



...
Wikipedia

...