The Ammonitida comprise the advanced Mesozoic ammonoidea found in the Phylloceratina, Lytoceratina, and Ammonitina. The Ammonitina are the most diverse containing at least nine superfamilies. The Phylloceratina and Lytoceratina are more conservative with the Phylloceratina including a single superfamily and the Lycoceratina maybe four.