Prionoceratoidea is a

superfamily SUPERFAMILY is a database and search platform of structural and functional annotation for all proteins and genomes. It classifies amino acid sequences into known structural domains, especially into SCOP superfamilies. Domains are functional, str ...

in the goniatitid suborder,

Tornoceratatina Tornoceratina is one of two suborders included in the Goniatitida, characterized by generally involute, subdiscoidal shells and by sutures in which the ventral ones are undivided. Sutural lobes increase in number during the course of life of th ...

that was

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

during the latter Paleozoic. The inclusive taxonomy of the Prionoceratoidea varies according to classification. In some, valid families are the Gattendorfiidae,

Prionoceratidae Prionoceratidae is one of seven families of the superfamily Prionoceratoidea, 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 m ...

, Pseudarietitidae, and Voehringeritidae. Others may add the Acrocanitidae,

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 ex ...

, Praeglyphioceratidae, and Sporadoceratidae to the list although it is not at all clear that these belong.

References

GONIAT - Prionocerataceae entry
11-28-11
Paleobiology Database - Prionocerataceae entry
11-28-11 *Saunders, Work, and Nikolaeva, 1999. Evolution of Complexity in Paleozoic Ammonoid Sutures -Supplementary Material.

Prionocerataceae, Tornoceratina Goniatitida superfamilies {{Goniatitida-stub