This previously unknown mass extinction gave rise to dinosaurs, scientists say

The newly identified mass extinction event helped dinosaurs to dominate the Earth.

(CNN)The asteroid strike that doomed the dinosaurs is an event that many people are aware of. It wiped out more than three-quarters of all life on Earth 66 million years ago.

But it was only one of the Big Five mass extinctions the planet has experienced since living organisms evolved 3.5 billion years ago, and wasn't the worst.
Now, scientists say they have identified evidence of a new mass extinction event in the fossil record, and it's one that allowed dinosaurs to dominate the Earth for more than 200 million years.
    It took place 232 million to 234 million years ago and has been called the Carnian Pluvial Episode.
      "So far, palaeontologists had identified five 'big' mass extinctions in the past 500 million years of the history of life," said study co-author Jacopo Dal Corso, a geologist at China University of Geosciences at Wuhan, in a news statement.
      "Each of these had a profound effect on the evolution of the Earth and of life. We have identified another great extinction event, and it evidently had a major role in helping to reset life on land and in the oceans, marking the origins of modern ecosystems."
      The cause, the researchers said, was most likely massive volcanic eruptions in what is now western Canada, where huge volumes of volcanic basalt was poured out and ultimately formed much of the western coast of North America.
        "The eruptions were so huge, they pumped vast amounts of greenhouse gases like carbon dioxide, and there were spikes of global warming," Dal Corso said.
        The change in the climate caused major biodiversity loss in the ocean and on land. Just after the extinction event new groups took over, forming more modern-like ecosystems. The shifts in climate encouraged growth of plant life, and the expansion of conifer forests -- the largely evergreen trees we know today with needles and cones.
        Summary of major extinction events through time, highlighting the newly identified Carnian Pluvial Episode at 233 million years ago.
        It wasn't just dinosaurs. Many modern groups of plants and animals also appeared at this time, including some of the first turtles, crocodiles, lizards and the first mammals.
        The Carnian Pluvial Episode also had an impact on ocean life, with 33% of marine life disappearing, a