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Age of Dinosaurs

Dinosaur extinction

Dead and dying dinosaursDead and dying dinosaurs For about 165 million years, the dinosaurs ruled unchallenged. During this long period, hundreds of different kinds of dinosaurs evolved. They lived and died, some leaving behind their fossils in the rocks. Then, quite suddenly, about 66 million years ago, they were gone. There are no more fossils of dinosaurs after this time, the end of the Cretaceous Period. Not only did the dinosaurs die out; so, too, did the marine reptiles and pterosaurs, many kinds of shellfish and a huge number of other land animals and plants. Altogether around 65–70% of life on Earth vanished for ever. The sudden death of so many living things is called a mass extinction. What caused this terrible disaster?

The K-Pg asteroid approaches EarthThe K-Pg asteroid approaches Earth

Asteroid collision

The evidence shows that the event was quite abrupt. It is thought by many scientists that it was triggered by a large asteroid crashing into Earth. The resulting explosion filled the atmosphere with dust, blotting out the sun and lowering temperatures for years on end. Plants withered away and, with them, the plant-eating dinosaurs, perishing from cold and hunger. Having no prey, the flesh-eaters soon followed. The Age of Dinosaurs was over. Or was it? Birds, close relatives of small, feathered dinosaurs, survived, so it could be said that dinosaurs live on to this day.

A mass extinction on almost the same scale as the K-Pg extinction, in which large numbers of large amphibian and non-dinosaur reptile species were wiped out, took place at the end of the Triassic Period.

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