The main cause of the destruction of dinosaurs, around 66 million years ago, is known to be the asteroid impact. But the exact mechanisms that linked the extinction effect are not clear, although climate change is thought to have played a part.
To understand how the devastation and associated climate change affected particular ecosystems, a team of McGill scientists has studied microscopic remains of plants from this period, which in river sediments in southern Saskatchewan. In a recent article in Palaeogeography, Palaeoclimatology, Palaeoecology they show that, in this area, local plant communities and ecosystems have moved long-term towards fewer aquatic plants and an increase in terrestrial plants, including trees such as birch and elms. The researchers claim that this increase was due to the extinction of dinosaurs eating large plants. They also found that, unexpectedly, changes in rainfall patterns at the extinction event were relatively small and short-lived.
“This could be important as we look to the future of global warming, where many scientists have predicted that changes in rainfall could have a major impact on humans and ecosystems. , “said Peter Douglas of McGill’s Department of Earth and Planning Scientists and senior author of the paper.” At other times of climate change in Earth’s history, we usually see evidence for such changes. The absence of such a sign at the event of a recent extinction is an interesting one. “
Douglas said, “Surprisingly, scientists know more about what happened in the late Cretaceous oceans than on land. By highlighting the environmental changes that took place at the time. this, we kept down the factors that are likely to extinct dinosaurs .. The research also provides an important analogue for human-caused environmental changes to the planet, and their potential for extinction in the future. “
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