The Eden Valley in Cumbria, UK during the Permian period

Permian period

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

Ended: Permian mass extinction
248 million years ago

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What the Earth was like

A map of the Earth in the Permian Period

Reconstruction of the Earth in the Permian period, 290 million - 248 million years ago. Credit: Dr Ron Blakey, NAU Geology.

Causes of extinctions

During this period the following events are thought to have contributed to the Permian mass extinction.

Catastrophic methane release Catastrophic methane release
Catastrophic methane release has been suggested as a possible cause of mass extinction. Methane clathrate is an ice-like substance formed from water and methane in the sea bed, arctic lakes and permafrost.
Flood basalt eruptions Flood basalt eruptions
Flood basalt eruptions are a type of large-scale volcanic activity, both in terms of extent and duration, that can occur on land or on the ocean floor. A flood basalt may continue to erupt for tens of thousands - possibly millions - of years and the lava can cover hundreds of thousands of kilometres.
Climate change Climate change
Earth's climate is not constant. Over geological time, the Earth's dominant climate has gone from ice age to tropical heat and from steamy jungles to searing deserts.