~252 million years agoReputable sourceWell documented
The Great Dying: The Permian Extinction
On the timeline · around ~252 million years ago · Mesozoic
What happened
The largest mass extinction in Earth's history struck about 252 million years ago, wiping out up to 96% of marine species. It is linked to enormous volcanic eruptions in what is now Siberia, which drove global warming, acid rain, and the poisoning of the oceans.
Why it matters
The 'Great Dying' nearly ended complex life on Earth; its aftermath cleared the way for new groups — including the ancestors of dinosaurs and mammals — to rise.