What will be an ideal response?
Sixty-five million years ago, at the end of the Cretaceous period, over 75 percent of the species on
Earth, including the dinosaurs, became extinct. Scientists have found a thin layer of clay all over the world that was laid down at that time, and it is rich in the element iridium—common in meteorites but rare in Earth’s crust. This suggests that an impact occurred that was large enough to have altered Earth’s climate and caused the worldwide extinction.
Thank you soo much!