Hoplitaceae is a superfamily of mostly Upper Cretaceous ammonites comprising families united by a similar suture pattern with multiple similar elements that tend to decrease in size going toward the umbilicus, at the inner edge of any whorl, and which are typically in a straight line. Sutural elements are commonly ammonitic, but in some saddles and in others both saddles and lobes are smooth and undivided. Shells are variable in form, both ribbed, evolute forms and smooth, involute forms are included.

Families regarded as part now include the Engonoceratidae

Engonoceratidae

Engonoceratidae is a family of typically compressed, more or less flat sided and involute ammonites from the mid Cretaceous belonging to the Hoplitaceae. shells have flat sided outer rims , at least in some stage. Single or branching irregular ribs and variably placed tubercles may occur...

, Hoplitidae

Hoplitidae

The Hoplitidae is a family of Cretaceous ammonites that lived during the middle of the period from the late Aptian to the Cenomanian. They are part of the superfamily Hoplitaceae....

, Placenticeratidae

Placenticeratidae

The Placenticeratidae is a family of mostly Late Cretaceous ammonites included in the superfamily Hoplitaceae, derived from the Engonoceratidae by an increase in suture complexity....

, and Schloenbachiidae

Schloenbachiidae

Shloenbachiidae is a family of hoplitacean ammonoid cephalopds mostly from the lower Upper Cretaceous, .Shloenbachiidae can be recognized by their usually keel bearing, irregularly ribbed and tuberculate shells that vary from evolute to rather involute and compressed to inflated...

 . Some classifications however include the Forbesiceridae in place of the Engonoceratidae

The older version of the Treatise includes in addition to the five famillies already mentioned, the Pulchelliidae, Trochleiceratidae, Douvilleiceratidae, Deshayesitidae, and Leymeriellidae, which have since been reassigned.