Specimens of coral fossils, part of the Museum coral collections from the Devonian, Carboniferous and Permian Rugose and tabulate corals were highly diverse during the Palaeozoic Era, 541 to 252 million years ago. But coral became extinct 251 million years ago along with at least 95 per cent of life on Earth. It was the most extreme mass extinction in history, triggered by high levels of carbon dioxide in the atmosphere, released from tens of thousands of volcanic eruptions in a large area of Siberia. It changed the marine habitat irrevocably. A99