Permian-Triassic /newsroom/taxonomy/term/19080/all en Fossil discovery reveals complex ecosystems existed on Earth much earlier than previously thought /newsroom/channels/news/fossil-discovery-reveals-complex-ecosystems-existed-earth-much-earlier-previously-thought-345984 <p>About 250 million years ago, the Permian-Triassic mass extinction killed over 80 per cent of the planet's species. In the aftermath, scientists believe that life on earth was dominated by simple species for up to 10 million years before more complex ecosystems could evolve. Now this longstanding theory is being challenged by a team of international researchers – including scientists from ƽÌØÎå²»ÖÐ and Université du Québec à Montréal.</p> Thu, 09 Feb 2023 14:41:04 +0000 shirley.cardenas@mcgill.ca 290349 at /newsroom