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Age of Dinosaurs

Why did the dinosaurs die out?

T. rex suffers the loss of its plant-eating prey.T. rex suffers the loss of its plant-eating prey.The dinosaurs, along with a large number of other species, died out quite abruptly at the close of the Cretaceous Period, 66 million years ago. Apart from sea turtles and crocodiles, no large animal survived. Altogether, around two-thirds of life on Earth vanished for ever. The sudden death of so many living things is called a mass extinction. From studying their fossils, we know that the dinosaurs dominated life on Earth for around 165 million years. Then quite suddenly they vanished from the fossil record. What could have caused this terrible disaster?

Rock from the K-Pg boundary, with a layer of clayRock from the K-Pg boundary, with a layer of clay

K-Pg boundary

Layers of sedimentary rock represent periods in the Earth's history. If something happened to explain why the dinosaurs died out at the end of the Cretaceous Period, then a close examination of the boundary between rocks laid down in the Cretaceous and those in the period following it, the Palaeogene, might reveal the answer. 

In March 2010, an international panel of 41 scientists decided that the Chicxulub asteroid collision was the cause of the extinction of the dinosaurs. They ruled out all other theories, such as supervolcano eruptions.

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