This picture shows how an artist thinks a big rock from space hit Earth. Some scientists think that a big rock hitting Earth could have killed all the dinosaurs millions of years ago.
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Courtesy of NASA
New Blow for Dinosaur-Killing Asteroid Theory
News story originally written on April 27, 2009
Many scientists have thought for years that the dinosaurs went extinct
because an asteroid
hit Earth near Mexico in a place called Chicxulub and caused big changes in the Earth’s climate.
Now, scientists have found new evidence that shows it was not an asteroid that killed the dinosaurs. The scientists discovered this by studying the rocks below the crater at Chicxulub. The rocks showed that animals and plants survived after the asteroid hit the Earth, and so when they went extinct it was caused by something else.
The scientists say that the dinosaurs’ extinction was probably caused by volcanoes. When they erupted, the volcanoes would have created lots of dust in the atmosphere and blocked sunlight from reaching Earth’s surface.
Lack of sunlight meant that plants could not photosynthesize and support the life of other animals on earth.
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