What is "dimorphoceratidae"

Dimorphoceratidae is one of two families included in the Dimorphocerataceae, a superfamily of ammonoid cephalopods belonging to the Goniatitida that lived during the Late Paleozoic. They are dimorphocerataceans in which the external lateral lobes and prongs of the ventral lobe are bifid. The shells are strongly involute, subdiscoidal to lenticular.