(Psittacosaurus,(Yinlong,(Wannanosaurus,((Goyocephale,(Homalocephale,(Tylocephale_gilmorei,(Foraminocephale_brevis,(Amtocephale_gobienses,(Prenocephale_prenes,Acrotholus_audeti,((Pachycephalosaurus,Alaskacephale_gongloffi,(Dracorex_hogwartsia,Stygimoloch_spinifer)),(Sphaerotholus_goodwini,Sphaerotholus_buchholtzae)))))))),(Hanssuesia_sternbergi,Colepiocephale_lambei,Stegoceras_validum,Stegoceras_novomexicanum)))));