Paratornoceratinae

Paratornoceratinae is a subfamily of oxyconic dimeroceratids included in the order Goniatitida, a group of Paleozoic ammonoids, which have closer affinity to living coleoids than to Nautilus.

Paratornoceratinae as defined by Ebbighausen, Becker, & Bockwinkel in 2002 comprises three recognised genera with sharp, oxyconic, venters; Acrimeroceras, Paratornoceras, and Polonites. The shell, as described for the type, Paratornoceras, is subglobular and evolute on young stages, but discoidal and with closed umbilicus in the adult.