Question: what extinction event has caused the most severe long term damage

Liam Herringshaw answered on 9 Jan 2026:

As far as we know, the end-Permian mass extinction around 252 million years ago was the biggest of these events, with over 90% of species disappearing. Other mass extinctions saw >75% of species die off too, but the end-Permian event was especially severe because it wiped out more than 50% of families too. This meant that whole branches of the tree of life disappeared, and ecosystems took millions of years to recover.