Jurassic: 199–145 million years ago

Birds and mammals evolve in the shadows of dinosaurs

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Illustration of a mid Jurassic plant community.
Image: Karen Carr
Source: Karen Carr

200 million years ago.
Image: Ron Blakey. Altered by Cally Bennet and Fons VandenBerg
Source: Colorado Plateau Geosystems


Dinosaurs thrived in a world that was generally warm and had large areas of forest. The first mammals evolved beneath the shadow of the dinosaurs, and one group of dinosaurs gave rise to the first birds. The diverse ocean life included many species of fishes, marine reptiles and invertebrates.

Although Australia was quite close to the south pole it had a relatively warm climate, and the land was covered with forests of tropical conifers, podocarps and cycads. Dinosaurs large and small were dominant on land across the globe, although only a few of Australia’s dinosaurs are known from this time. Marine reptiles such as long-necked plesiosaurs hunted in the sea, and large cephalopod molluscs called ammonites caught prey with their tentacles. The movement of the Earth’s crust gradually began to break up Gondwana, and Australia started to pull away from Antarctica.


Objects from the Jurassic


Dinosaur Walk

More about Jurassic animals at Dinosaur Walk.