Wikipedia
Ochetoceratinae
The Ochetoceratinae is a subfamily within the Oppeliidae from the Upper Jurassic, shells of which are typically oxycones with a tricarinate venter and falcoid ribbing, commonly divided by a medain lateral groove or fillet. The median (middle) keel is the tallest.
The Ochetoceratinae may be polyphyletic, derived from both the Oppeliidae and Hecticoceratinae as suggested by differences in the included genera.