Dawn of the Dinos

Long ago, a heavy rain began to fall on Earth. It beat down, on and off, for a million years! In a recently published study, scientists revealed that this super soaker event likely paved the way for the biggest dinosaurs to roam the planet.

Called the Carnian Pluvial Episode (CPE), this rainy spell took place about 232 million years ago. What was once a desertlike planet suddenly turned warmer and wetter.

Researchers say volcanic eruptions in what is now Western Canada were to blame. The massive eruptions pumped huge amounts of carbon dioxide and other gases into the air. That warmed the planet, causing some of the seas to evaporate, which led to all the rain.

The change in climate killed off many plants and animals, which could not adapt. But the CPE wasn’t all bad news. It also allowed other life-forms, like frogs, crocodiles, and dinosaurs, to evolve.

Some small dinosaurs had existed before the CPE, but they were rare. Then the million-year rains helped new species of plants and trees to grow. These new sources of food helped give rise to huge new dinosaurs that would rule the planet for the next 150 million years.

Geologist Michael Simms studies fossils from the CPE. He says without the CPE, the world may have looked very different.

“The Tyrannosaurus, Triceratops, and Stegosaurus probably wouldn’t have existed,” explains Simms.