Opinions from H. You and P. Dodson 2004
- 'Archaeoceratops belongs to Neoceratopsia'
- 'Archaeoceratops oshimai belongs to Archaeoceratops'
- 'Asiaceratops is a nomen dubium'
- 'Asiaceratops salsopaludalis is a nomen dubium'
- 'Bagaceratops rozhdestvenskyi belongs to Bagaceratops'
- 'Breviceratops is a subjective synonym of Bagaceratops'
- 'Chaoyangsaurus belongs to Neoceratopsia'
- 'Chaoyangsaurus youngi belongs to Chaoyangsaurus'
- 'Graciliceratops belongs to Neoceratopsia'
- 'Graciliceratops mongoliensis belongs to Graciliceratops'
- 'Kulceratops is a nomen dubium'
- 'Kulceratops kulensis is a nomen dubium'
- 'Leptoceratops belongs to Neoceratopsia'
- 'Leptoceratops cerorhynchus is recombined as Montanoceratops cerorhynchus'
- 'Leptoceratops gracilis belongs to Leptoceratops'
- 'Liaoceratops belongs to Neoceratopsia'
- 'Liaoceratops yanzigouensis belongs to Liaoceratops'
- 'Microceratops is a nomen dubium'
- 'Microceratops gobiensis is a nomen dubium'
- 'Microceratops sulcidens is a nomen dubium'
- 'Montanoceratops belongs to Neoceratopsia'
- 'Neoceratopsia belongs to Ceratopsia'
- 'Protiguanodon is a subjective synonym of Psittacosaurus'
- 'Protiguanodon mongoliense is a subjective synonym of Psittacosaurus mongoliensis'
- 'Protoceratops belongs to Neoceratopsia'
- 'Protoceratops andrewsi belongs to Protoceratops'
- 'Protoceratops hellenikorhinus belongs to Protoceratops'
- 'Breviceratops kozlowskii is a subjective synonym of Bagaceratops rozhdestvenskyi'
- 'Psittacosauridae belongs to Ceratopsia'
- 'Psittacosaurus belongs to Psittacosauridae'
- 'Psittacosaurus guyangensis belongs to Psittacosaurus'
- 'Psittacosaurus mazongshanensis belongs to Psittacosaurus'
- 'Psittacosaurus meileyingensis belongs to Psittacosaurus'
- 'Psittacosaurus mongoliensis belongs to Psittacosaurus'
- 'Psittacosaurus neimongoliensis belongs to Psittacosaurus'
- 'Psittacosaurus ordosensis belongs to Psittacosaurus'
- 'Psittacosaurus osborni belongs to Psittacosaurus'
- 'Psittacosaurus sattayaraki is a nomen dubium'
- 'Psittacosaurus sinensis belongs to Psittacosaurus'
- 'Psittacosaurus tingi is a subjective synonym of Psittacosaurus osborni'
- 'Psittacosaurus xinjiangensis belongs to Psittacosaurus'
- 'Psittacosaurus youngi belongs to Psittacosaurus'
- 'Turanoceratops is a nomen dubium'
- 'Turanoceratops tardabilis is a nomen dubium'
- 'Udanoceratops belongs to Neoceratopsia'
- 'Udanoceratops tschizhovi belongs to Udanoceratops'
- 'Zuniceratops belongs to Neoceratopsia'
- 'Zuniceratops christopheri belongs to Zuniceratops'