Norian Stage

Geologic Age

• 227–208.5 Ma

Eon / Era / Period / Epoch

• Phanerozoic; Mesozoic; Triassic; Late Triassic

What happened during this time?

• Sauropodomorph dinosaurs begin to have success on land. 

• Herbivorous therapsids (the large Dicynodonts and medium-sized traversodonts) decline on land. 

  • The success of dinosaurs over therapsids seems to be due to climatic factors

  • The increasing aridity meant that the moist biome that had enabled the therapsids to flourish had now become a narrow equatorial strip [Olsen et al 2001], bordered by deserts and semi-deserts to both north and south.