Fast the oceans have become hostile to life

A team of German, Belgian, American and Chinese geologists examined climatic cycles in different rock formations to determine the precise timing of the Devonian extinction. Their results, published this week , reveal how quickly the oceans became hostile to life during the Devonian period. In whole Earth's history, geologists distinguish five mass extinction events that were particularly severe. The Devonian mass extinction event is one of those five and occurred 374 million years ago, more than 300 million years before the meteorite impact that wiped out the dinosaurs. The Devonian was a very peculiar period: large fish reigned the oceans and coral reefs were flourishing, but there were no large land animals yet. "The Devonian climate can be best described as an extreme greenhouse climate, with much more CO₂ in the atmosphere compared to today," says David De Vleeschouwer, geologist at the MARUM - Center for Marine Environmental Sciences at the University of Bremen. Despite the intriguing aspects of the Devonian world, scientists did not know exactly how fast the Earth became inhospitable for life across Devonian mass extinction event.