Plot of extinction intensity (percentage of marine genera that are present in each interval of time but do not exist in the following interval) vs time in the past.[1] Geological periods are annotated (by abbreviation and colour) above. The Permian–Triassic extinction event is the most significant event for marine genera, with just over 50% (according to this source) perishing. (source and image i
![Permian–Triassic extinction event - Wikipedia](https://cdn-ak-scissors.b.st-hatena.com/image/square/e77917dcd6d627358c2872f4ae9a9e6e2ff274e7/height=288;version=1;width=512/https%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2F0%2F06%2FExtinction_intensity.svg%2F1200px-Extinction_intensity.svg.png)