Our episode tonight takes us way back to 252 million years ago, at the end of the Permian geologic period. We will discover what marine life was like in the gigantic ocean called Panthalassa, as well as the flora and fauna of the supercontinent Pangea. In the last millions of years of the Permian, marine and land species began to go extinct in larger and larger numbers, culminating in the last million years in the most severe extinction event observed in the history of our planet. What are the possible causes of this extinction: volcanism, climate change, collision with a meteorite...?