smithsonianmag.com
Roughly a quarter of a billion years ago, an apocalypse struck the Earth. Known as the Great Dying, it claimed more lives than any other mass extinction known to science, including the one that did in the non-avian dinosaurs 65 million years ago. Over 90 percent of all species on the planet were wiped out, from armor-clad trilobites in the oceans to giant reptiles on land. The host of strange creatures vanished, giving way to the ancestors of modern flora and fauna.