Wikipedia
Stephanoceratoidea
Stephanoceratoidea, formerly Stephanocerataceae, is a superfamily of middle Jurassic ammonoid cephalopods within the order Ammonitida containing diverse forms, generally with sharp ribbing and complex suture lines. Aptychi are believed to be mostly granular (Granulaptycus) or concentrially ribbed on the surface (Praestriaptychus) (Arkell et al. 1957)