New rock dating techniques have helped narrow the timeframe of a chain of massive volcanic eruptions that wiped out half the world's species 200 million years ago, a study said Thursday. The result is the most precise date yet -- 201,564,000 years ago -- for the event known as the End-Triassic Extinction, or the fourth mass extinction, said the study in the journal Science. The eruptions "had to be a hell of an event," said co-author Dennis Kent, a paleomagnetism expert at Columbia University's Lamont-Doherty Earth Observatory. They may offer a historic parallel to the human-caused climate change happening today, by showing how sharp increases in carbon dioxide can outpace vulnerable species' ability to adapt, researchers said. The new analysis winnows the estimated date from its previous range of up to three million years to 20,000 years at most, a blink of an eye in geological terms. The eruptions caused an already hot Earth to become even more stifling, killing...
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