article_snippet.sent: Ordovician-Silurian mass extinction - 443.4 million years ago .
article_snippet.sent: Ordovician-Silurian mass extinction - 443.4 million years ago was the third largest extinction in Earth's history, and had two peaks of dying separated by hundreds of thousands of years.
article_snippet.sent: Late Devonian mass extinction - 375-359 million years ago .
article_snippet.sent: Permian mass extinction - 252 million years ago .
article_snippet.sent: Permian mass extinction - 252 million years ago has been nicknamed The Great Dying, since an incredible 96 per cent of species died out.
article_snippet.sent: Triassic-Jurassic mass extinction - 201 million years ago .
article_snippet.sent: Cretaceous-Tertiary mass extinction - 66 million years ago .
article_snippet.sent: Cretaceous-Tertiary mass extinction - 66 million years ago was the event that wiped out the dinosaurs.