Local die-offs of marine life can result. But Wignall suspects that the entire ocean may have stagnated in Permian times. What could still the currents that oxygenate the ocean? Perhaps a lack of ...

As carbon dioxide (CO2) levels rose at the end of the Permian ... which is why marine extinctions happened later – when global warming became more intense. Dr Sun said: ‘Most life failed ...

The environment also became more hospitable, with a warming climate and rising sea levels flooding low-lying landmasses to create shallow, marine habitats ideal for spawning new life-forms.