Permian–Triassic extinction event
The Permian/Triassic extinction event was the largest extinction event in the Phanerozoic eon. 57% of all biological families, 83% of all genera, 96% of all marine species became extinct. This includes many fish and the last surviving trilobites, 70% of all terrestrial vertebrates and many of the large amphibia, primitive reptiles and synapsids.  It is the only known extinction event of insects. It ended the Palaeozoic era, and began the Mesozoic era.