New data has confirmed that the extinction of the dinosaurs began long before the fall of the asteroid

New data has confirmed that the extinction of the dinosaurs began long before the fall of the asteroid
New data has confirmed that the extinction of the dinosaurs began long before the fall of the asteroid
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Non-avian dinosaurs began to lose in the struggle for survival millions of years before the Cretaceous-Paleogene extinction, and this is due to the cooling and the emergence of more advanced competitors.

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All non-avian dinosaurs became extinct during the Cretaceous-Paleogene extinction, about 66 million years ago. It is believed that it was launched by the fall of a massive celestial body that hit the Earth, across the territory of what is now Mexico. However, some data suggest that the era of dinosaurs would have come to an end without this catastrophe: by that time they were far from the best period of their evolutionary history, and the meteorite put only a fat point at the end.

The state of dinosaurs before the fall of the asteroid remains controversial: many scientists believe they could have flourished for a long time. However, this possibility is rejected by the results of the new work of French paleontologists led by Fabien Condamine, which is presented in the journal Nature Communications. Comparing data on more than 1,600 remains of ancient reptiles, scientists found that they began to lose the race for survival long before the asteroid hit.

The authors have compiled information on known remains of key non-avian dinosaur families between 66 million and 150 million years old. The representatives of ankylosaurids, hadrosaurids, ceratopsids, dromaeosaurids, troodontids and tyrannosaurids, which were once widespread throughout the world, were considered. Scientists have traced how their diversity changed until extinction, at what pace new species appeared and old ones disappeared.

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The work showed that for a long time both processes proceeded in a balanced manner, without sharp changes in speed. However, about 76 million years ago - about 10 million years before the fall of the asteroid - the rate of extinction of species began to increase sharply, and the formation of new ones slowed down in all the families considered. This indicates that dinosaurs were no longer able to keep up with the pace of environmental change, and more adapted species did not appear fast enough to replace those that failed to adapt.

The authors associate these processes with the emergence of a group of hadrosaurs - one of the most perfect non-avian dinosaurs that began to displace herbivorous competitors everywhere. This could trigger whole "chains of extinctions", affecting the state of predators hunting them and destabilizing entire ecosystems. Global cooling, the first signs of which appeared about 100 million years ago, could be an equally important factor. According to scientists, these reasons could trigger the extinction process long before the meteorite hit the Earth.

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