Engonoceratidae is a family of typically compressed, more or less flat sided and involute ammonites (cephalopod order Ammonitida) from the mid Cretaceous belonging to the Hoplitaceae. shells have flat sided outer rims ( venters), at least in some stage. Single or branching irregular ribs and variably placed tubercles may occur. Sutures have numerous auxiliary and adventive elements of similar form, in general radially arranged. Forwardly divergent saddles tend to be simple, without subdivision. Lobes, pointing apically, may be simple and undivided or may be frilled with short irregular serrations.