Tornoceratids are subdiscoidal goniatitids with biconvex growth lines and sutures that form 6 to 10 lobes, the ventral one undivided, the lateral ones originating as subdivisions of external and internal lateral saddle.

The Tornoceratinae form the root stock of the tornoceratids and are derived from Anarcestida.

The Tornoceratinae includes Tornoceras, Epitornoceras, Lobotornoceras, Protornoceras, and Tornia, described in the Treatise (L 1957), along with Crassotornoceras, Linguatornoceras, Domanikoceras, Simcheiloceras, and Oxytornoceras which were added later.

Aulatornoceras, type for the Aulatornoceratinae was previously considered a subgenus of Tornoceras and is known from the Upper Devonian of North America and Europe.

Genera making up the Falcitornoceratinae form an evolutionary series, Phoenixites, Falcitornoceras, Gundolficeras, Exotornoceras, leading up to Posttornoceras, type genus of the Posttornoceratidae.