The KT boundary shows evidence that a small asteroid hit the earth, which is the best explanation for that mass extinction 65 million years ago. The causes of the other mass extinctions (about 4 of them) have not been determined.
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The KT boundary shows evidence that a small asteroid hit the earth, which is the best explanation for that mass extinction 65 million years ago. The causes of the other mass extinctions (about 4 of them) have not been determined.