About 250 million years ago, at the end of the Permian period, something killed some 90 percent of the planet's species. Less than 5 percent of the animal species in the seas survived. On land ...

or "life oasis," for terrestrial plants during the end-Permian mass extinction, the most severe biological crisis since the Cambrian period. The discovery, led by Prof. Liu Feng, from the Nanjing ...