Before the dinosaurs came to prominence, the world was ruled by armour-plated crocodile-like creatures called crurotarsans.
At that time most of the planet’s land was concentrated into one super-continent called Pangaea, and there was no Atlantic Ocean.
Then, just over 200 million years ago, Pangaea was broken up by mighty forces within the Earth’s crust.
The tectonic plates supporting present-day North America and Africa drifted apart, creating an opening that was destined to become the Atlantic Ocean. At the same time the upheaval triggered massive volcanic eruptions.
Outflows of lava covered more than 3.5 million square miles of the Earth’s surface, an area roughly equal to the United States.
The volcanic activity led to an upsurge in carbon dioxide and other greenhouse gases and destroyed half the plant species on Earth.
At the end of the Triassic period, carbon dioxide levels were 10 times higher than they are today and the planet was in the grip of a ”hot house” climate.
Scientists pieced the events together by combining fossil finds with the carbon signature found in the preserved remains of ancient leaves and wood.
They established that after the lava flows, the crurotarsan fossil record was ”nearly completely gone”.
The crurotarsans had been competing strongly with the earliest dinosaurs, which were then limited in size but went on to become some of the biggest land animals ever known.