PachycephalosauriaChaoyangsaurusPsittacosauridaeLiaoceratopsArchaeoceratopsIGM_100_slash_1315GraciliceratopsBagaceratopsProtoceratopsZuniceratopsCentrosaurusTriceratopsCerasinopsUdanoceratopsLeptoceratopsMontanoceratopsPrenoceratopsOsteologyMaximum ParsimonyBased on reanalysis of the original matrix.Chinnery_et_Horner_2007a