Climate crisis 233m years ago reshaped life on Earth, say scientists
A mass extinction event sparked by a sudden shift in climate more than 200m years ago reshaped life on Earth and ushered in the age of the dinosaurs, scientists claim.
An international team reviewed geological evidence and the fossil record and found that enormous volcanic eruptions in what is now western Canada coincided with a global loss of plants and animals.
But while the crisis 233m years ago wiped out great segments of life, it set the stage for the dinosaurs to take over, and for some of the first mammals, crocodiles and turtles to extend their ranges.
“There was clearly a mass extinction that we now call the Carnian Pluvial Episode, which was a bit hidden and mystical,” said Mike Benton, a palaeontologist at Bristol University. “It brought an opportunity for the dinosaurs, which would have been the obvious things you would see, but also mammals, turtles and others.”
Jacopo Dal Corso, who worked on the project at Leeds University, said geochemical signatures from the time point to massive volcanic eruptions which pumped vast amounts of greenhouse gas into the air. These drove repeated spikes in global warming. Dal Corso traced them back to the Wrangellia province of western Canada, where Triassic eruptions ejected volcanic basalt that now forms much of the west coast of North America.
The warming climate, and the heavier rains it brought, may have helped life at first. But the conditions became extreme and were followed by an extended arid period. Lush vegetation, such as seed ferns, died off and ...
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