Triassic: 251–199 million years ago

First dinosaurs

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A late Triassic plant community.
Image: Karen Carr
Source: Karen Carr

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


The severity of the extinction at the end of the Permian meant that recovery was slow. The surviving marine life struggled to recover from the lingering effects of the mass extinction, such as significantly lower oxygen levels. The extinction of many corals left an empty niche, which was only filled by the evolution of modern scleractinian corals later in the Triassic. It took coral reefs millions of years to reform.

Survivors on land included insects, plants, amphibious tetrapods and some reptile groups – among them the ancestors of mammals, dinosaurs and birds.

There are few sedimentary rocks in Victoria dating from this period, so our knowledge is limited about the animals and plants that existed then. We do know that the world had no polar ice caps. Victoria had a mild climate despite being near the south pole. We can imagine the valleys, previously carved by glaciers, were now green with conifer forests and an understorey of ferns. They were probably home to amphibious tetrapods, reptiles and the earliest dinosaurs and mammals.


Objects from the Triassic

Photograph of a yellow plastic Tyranasaurus Rex