Imagine a world on the brink of collapse: volcanic eruptions spewing toxic gases, oceans turning acidic, and up to 90% of Earth’s species vanishing in the blink of an eye. This was the reality at the end of the Permian Period, around 252 million years ago, during Earth’s most catastrophic mass extinction event. Imagine a world on the brink of collapse: volcanic eruptions spewing toxic gases, oceans turning acidic, and up to 90% of Earth’s species vanishing in the blink of an eye. This was the reality at the end of the Permian Period, around 252 million years ago, during Earth’s most catastrophic mass extinction event. Paleontology & Fossils Phys.org – latest science and technology news stories