While volcanoes have been forming, spewing, and dying throughout the planet's history, we can only learn about prehistorical eruptions by examining geology. That's what paleontologist Paul Wignall of the University of Leeds did for a study just published in Science. His team found a layer of igneous rock in Southwest China, and used the marine fossils to date it to a huge volcanic eruption 260 million years ago.

They believe this huge blast caused the so-called mid-Permian extinction, which killed off species around the world. While not as catastrophic as the "great dying" 9 million years later that killed up to 96 percent of marine species, this blast certainly shows how that volcanoes are not to be trifled with.