Oppeliidae
Encyclopedia
Oppeliidae are compressed to oxyconic, sculptured Haplocerataceae
Haplocerataceae
Haplocerataceae is a superfamily of ammonoid cephalopods belonging to the Ammonitida that unites three families, the Strigoceratidae, Oppeliidae, and Haploceratidae, listed below....

, either unkeeled, unicarinate, bicarinate, or tricarinate; with sutures in great variety, but ribbing usually more or less falcoid or falcate. The Oppeliidae is the principal family of the Haplocerataceae, with the longest durantion, extending from the Middle Jurassic (Bajocian) to the Upper Cretaceous (Cenomanian) Their derivation is from the Hildocerataceae
Hildocerataceae
Hildocerataceae is a superfamily of compressed or planulate ammonites, some tending to develop acute outer rims; generally with arcuate or sigmoidal ribs. Aptichus were found in place are double-valved....

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Subfamilies

Nine subfamilies are recognized, the first 8 of which are include in the earlier Treatise, Part L. They are the
Oppeliinae
Hecticoceratinae
Distchoceratinae
Teramelliceratinae
Phlycticeratinae
Streblitinae
Mazapilitinae
Aconeceratinae
Binneyitinae

The Binneyitinae was added by Donovan et al, 1981. transferred from the Stephanocerataceae
Stephanocerataceae
Stephanocerataceae is a superfamily of middle Jurassic ammonoid cephalopods within the order Ammonitida containing diverse forms, generally with sharp ribbing and complex suture lines...

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