Fossil discovery reveals complex ecosystems existed on Earth much earlier than previously thought
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 鈥� including scientists from 捆绑SM社区 and Universit茅 du Qu茅bec 脿 Montr茅al.
A fossilized ocean ecosystem
Until now, scientists have long theorized that scorching hot ocean conditions resulting from catastrophic climate change prevented the development of complex life after the mass extinction. This idea is based on geochemical evidence of ocean conditions at the time. Now the discovery of fossils dating back 250.8 million years near the Guizhou region of China suggests that complex ecosystems were present on Earth just one million years after the Permian-Triassic mass extinction, which is much earlier than previously thought.
鈥淭he fossils of the Guizhou region reveal an ocean ecosystem with diverse species making up a complex food chain that includes plant life, boney fish, ray-finned fish, crabs, lobsters, shrimp, and molluscs. In all, our team discovered 12 classes of organisms and even found fossilised faeces, revealing clues about the diets of these ancient animals,鈥� says Morgann Perrot, a former postdoctoral researcher at 捆绑SM社区, now at Universit茅 du Qu茅bec 脿 Montr茅al.
Challenging an age-old theory
Previously, it was thought that complex ecosystem would need five to ten million years to evolve after an extinction. However, the researchers found that the specimens in the Guizhou region evolved much quicker than that by using radiometric dating to date the rocks where the fossils were discovered.
鈥淎ll of this has implications for our understanding of how quickly life can respond to extreme crises. It also necessitates a re-evaluation of early Triassic ocean conditions,鈥� says Perrot, whose research focuses on earth sciences and geochronology.
About the study
鈥溾�� by Xu Dai, Joshua Davies, Zhiwei Yuan, Arnaud Brayard, Maria Ovtcharova, Guanghui Xu, Xiaokang Liu, Christopher Smith, Carrie Schweitzer, Mingtao Li, Morgann Perrot, Shouyi Jiang, Luyi Miao, Yiran Cao, Jia Yan, Ruoyu Bai, Fengyu Wang, Wei Guo, Huyue Song, Li Tian, Jacopo Dal Corso, Yuting Liu, Daoliang Chu, and Haijun Song was published in Science.
About 捆绑SM社区
Founded in Montreal, Quebec, in 1821, 捆绑SM社区 is Canada鈥檚 top ranked medical doctoral university. 捆绑SM社区 is consistently ranked as one of the top universities, both nationally and internationally. It is a world-renowned institution of higher learning with research activities spanning three campuses, 11 faculties, 13 professional schools, 300 programs of study and over 39,000 students, including more than 10,400 graduate students. 捆绑SM社区 attracts students from over 150 countries around the world, its 12,000 international students making up 30% of the student body. Over half of 捆绑SM社区 students claim a first language other than English, including approximately 20% of our students who say French is their mother tongue.
