The Permian started with an ice age and ended with the most devastating mass extinction the Earth has ever experienced. In fact, at least two mass extinctions occurred during this time. It's also when all the continents of the world finally coalesced into one supercontinent, named Pangaea (meaning 'the entire Earth'). As the globe warmed up and the ice retreated, many areas of Pangaea became very arid. The oxygen level plummeted too, from a high of 35% of the total atmosphere to around 15%. For comparison, today's oxygen content is 21%.
Began: 290 million years ago
Permian mass extinction
248 million years ago
Reconstruction of the Earth in the Permian period, 290 million - 248 million years ago. Credit: Dr Ron Blakey, NAU Geology.
During this period the following events are thought to have contributed to the Permian mass extinction.