Phylloceratina is a suborder of ammonites included in the Ammonitida thought to be derived from the Meekocerataceae and which give rise to the other ammonitid suborders. Shells are typically smooth to feebly ornamented. Saddle endings in the suture are typically phylloid, leaf-like. Unlike the other suborders in the Ammonitida, especially the Ammonitina which greatly diversified during both the Jurassic and Cretaceous, the Phylloceratina changed little during its existence.