Stephanocerataceae

Stephanocerataceae refers to a superfamily of middle and upper Jurassic ammonites (suborder Ammonitina) that range from the middle Bajocian to the lower Kimmeridgian. They are characterized by shells with sharp ribbing and a complex suture line with a dominant first lateral lobe and a well developed umbilical lobe.

The Stephanocerataceae involves three phyllogenic family groups, two starting with the bassal Otoitidae. First is the sequence of Stephanoceratidae, Thamboceratidae, and Clydoniceratidae which extends from the Bajocian barely into the Callovian. The second which consists, in phyllogenic order, of the Sphaeroceratidae, Tulitidae, Pachyceratidae, and Mayaititdae extends to the upper Jurassic Oxfordian. The third which has its origin the the Tuliidae consists of the Macrocephalitidae, Cosmoceratidae, and Cardoceritae. Not only do these familites vary is stratigraphic position, some overlapping, but in the general form of their shells.