Survivors (IMAGE) Brown University Caption Lystrosaurus, a relative to mammals, was one of a handful of "disaster taxa" to escape from the rubble of the Permian Period, along with the meter-high spore-tree Pleuromeia. Low diversity of animals delayed the full recovery of land ecosystems by millions of years. Credit Victor Leshyk Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.