Earliest occurrence of some clades

• Sauropoda – Isanosaurus – Norian

• Neosauropoda – Atlasaurus – Bathonian

• Diplodocoidea – [eleven genera] – Kimmeridgian

• Titanosauria – Tendaguria – Kimmeridgian

• Canosauria – Cryolophosaurus – Pliensbachian

• Coelurosauria – Eshanosaurus – Hettanginian

• Pachycephalosauria – Yaverlandia – Barremian

• Ceratopsia – Chaoyangosaurus – Middle Jurassic

• Ornithopoda – Yandusaurus – Bathonian

• Stegosauria – Huatangosaurus – Bathonian

• Ankylosauria – Tianchisaurus – Bathonian

Notes: