Permian-triassic extinction

AROUND 252 MILLION YEARS AGO

This extinction event, often referred to as the ‘Great Dying’, is the largest to ever hit Earth. It wiped out some 90 per cent of all the planet's species and decimated the reptiles, insects and amphibians that roamed on land. What caused this catastrophic event was a period of rampant volcanism. At the end of the Permian Period, the part of the world we now call Siberia erupted in explosive volcanoes. This released a large amount of carbon dioxide into the atmosphere, causing a greenhouse effect that heated up the planet. As a result, weather patterns shifted, sea levels rose and acid rain beat down on the land. In the ocean, the increased levels of carbon dioxide dissolved into the water, poisoning marine life and depriving them of oxygen-rich water. At the time the world consisted of one supercontinent called Pangaea, which some scientists believe contributed to a lack of movement in the world’s oceans, creating a global pool of stagnant water that only perpetuated carbon dioxide accumulation. Corals were a group of marine life forms worst affected, it took 14 million years for the ocean reefs to rebuild to their former glory.

How massive eruptions caused the biggest mass extinction on Earth

Some of the earliest land dinosaurs, such as dimetrodons, were among the first to become extinct