Prionocerataceae is a superfamily in the goniatitid suborder, Tornoceratatina that was extant

Extant

Extant is a term commonly used in biology to refer to taxa, such as species, genera and families, that are still in existence, meaning still alive.The term extant contrasts with extinct.-Example:...

 during the latter Paleozoic.

The inclusive taxonomy of the Prionocerataceae varies according to classification. In some, valid families are the Gattendorfiidae, Prionoceratidae, Pseudarietitidae, and Voehringeritidae.
Others may add the Acrocanitidae

Acrocanitidae

Acrocanitidae is one of seven families of the Prionocerataceae families, a member of the Goniatitida order. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.-References:* Neues...

, Cheiloceratidae

Cheiloceratidae

Cheiloceratidae is a family of ammonoid cephalopods included in the goniatitid suborder Tornoceratina in which the suture has 4 to 12 lobes, the ventral one undivided and those in the lateral areas originating as subdivisions of internal and external lateral saddles.-Taxonomy:The taxonomy of the...

, Praeglyphioceratidae

Praeglyphioceratidae

Praeglyphioceratidae is one of seven families of the Prionocerataceae families, a member of the Goniatitida order. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.-References:* ...

, and Sporadoceratidae

Sporadoceratidae

Sporadoceratidae is one of seven families of the Prionocerataceae families, a member of the Goniatitida order. They are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids.-References:* accessed...

to the list although it is not at all clear that these belong.