Mass extinctions have happened throughout Earth’s history, sometimes wiping out the large majority of all life on Earth.

Each spelled the end for millions of species—and the beginning for millions more that evolved to take their places.

On earlier EarthDates, we talked about the asteroid that smashed into Earth, ending the reign of the dinosaurs while opening the door for mammals.

But there was an earlier event that appears to have created the same opening for dinosaurs themselves.

Around 250 million years ago, dinosaurs made up only about 5 percent of animals on Earth.

Then a massive series of volcanic eruptions filled the atmosphere with carbon dioxide, which triggered dramatic global warming and extreme global rainfall.

The rain caused floods across the planet for many thousands of years. Floods alternated with periods of drought for 1 to 2 million years, to create an era so severe it earned its own geologic name: The Carnian Pluvial Episode.

It stressed all life on Earth, plants and animals, and removed many species that were poorly equipped for the harsh conditions.

By 2 million years after the Pluvial Episode, dinosaurs, who were better adapted for these conditions, exploded in population and variety, with new species filling empty environmental niches.

What happened for the dinosaurs, then happened to the dinosaurs—and it will happen again. In this way, life on Earth renews itself.