Zhao (1983:301) erected this taxon to contain pachycephalosaurids and a taxon cited as “Chaoyoungosaurus.” Later formally named Chaoyangsaurus youngi (Zhao et al. 1999), this taxon is clearly positioned a basal ceratopsian. Pachycephalosauroidea, in Zhao’s original sense, is polyphyletic. There may be some eventual use for this taxon, if there are a lot of discoveries at the base of Pachycephalosauria.