Key facts
- Marine environments were deteriorating long before the End-Triassic mass extinction.
- The End-Triassic mass extinction occurred approximately 201 million years ago.
- Chemical traces preserved in ancient rocks indicate this deterioration.
Evidence from ancient rocks suggests that oceans began losing oxygen millions of years prior to the End-Triassic mass extinction event. This catastrophic event, which took place around 201 million years ago, led to the demise of a significant number of species. The chemical traces found in these ancient rock formations indicate a gradual deterioration of marine environments, predating the mass extinction by a considerable period. This suggests that the conditions leading to the extinction were developing over a much longer timescale than previously understood.