Triassic (Mesozoic 1)

Mesozoic Era 1: Triassic Period – New Life Takes Hold

Key Events

  • The Triassic begins and ends with mass extinction events.
  • Life takes several million years to recover its former diversity.
  • The first dinosaurs appear towards the end of the period.
  • The first mammals evolve.
  • The first vertebrates take flight, becoming the pterosaurs.
  • Mid-way through the Triassic, Pangea starts to rift into Laurasia to the north and Gondwana to the south.
Illustration of life during the Triassic Period.
Illustration of life during the Triassic Period. Copyright: Vix Southgate

Facts, Debates & Trivia

  • The Triassic Period is named after a triple layer of rocks found in Germany.
  • Coal vanishes from the geological record at the start of the Triassic Period. Since coal forms from plants, this is probably due to the mass extinction event 251.9 million years ago.
  • The Sun takes approximately 225-250 million years to orbit the centre of our galaxy. Our Solar System was last at this position in the Milky Way during the Triassic Period.
The Earth Story Trail signs for the Mesozoic Era, which has three geological periods, the Triassic, the Jurassic and the Cretaceous.
The Earth Story Trail signs for the Mesozoic Era. Credit: Cornwall Sea to Stars/A Heward

Conditions

  • The climate is mainly hot and dry, with deserts spanning Pangea’s interior.
The Earth 240 million years ago. The red dot marks the location of what will eventually become Cornwall. Credit: C.R. Scotese/I. Webster

Timeline

251.9 – 201.3 million years ago

(50.6 million years)

1 metre = 10 million years

Where have you reached on the trail?