How did the 5 mass extinctions happen?

#1

The most recent one was because of a meteor. The Triassic-Jurassic extinction was because of massive volcanic eruptions. The Permian-Triassic extinction was because of volcanism as well. The late Devonian extinction was because of two pulses of cold temperatures that killed off many species that lived in the hot waters. The Ordovician- Silurian extinction was because of glaciation and a fall in sea levels.