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Originally Posted by Nokton
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There is no evidence that co relates an asteroid impact with a mass extinction. . . .
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Actually, dear friend, There is a great deal of evidence for an asteroid impact being responsible for a couple of mass extinctions:
SPACE.com -- The Five Worst Extinctions in Earth's History
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Cretaceous-Tertiary extinction, about 65 million years ago, probably caused or aggravated by impact of several-mile-wide asteroid that created the Chicxulub crater now hidden on the Yucatan Peninsula and beneath the Gulf of Mexico.
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As the article states, there are some that argue for other causes, but to my knowledge this asteroid impact is the most widely held reason for the extinction, perhaps aggravated by volcanic activity. Also keep in mind that this article is at least 7 years old. Note this fact for the quote below as well.
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Permian-Triassic extinction, about 251 million years ago. Many scientists suspect a comet or asteroid impact, although direct evidence has not been found. Others believe the cause was flood volcanism from the Siberian Traps and related loss of oxygen in the seas. Still others believe the impact triggered the volcanism and also may have done so during the Cretaceous-Tertiary extinction. The Permian-Triassic catastrophe was Earths worst mass extinction, killing 95 percent of all species, 53 percent of marine families, 84 percent of marine genera and an estimated 70 percent of land species such as plants, insects and vertebrate animals.
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However, recently there is evidence that an asteroid impact was a major player in this extinction - there is ongoing investigation into an impact zone in Australia that correlates with the time of this extinction. To my knowledge, this impact could very well have triggered much volcanism as well.
I should probably have done more supporting research, and I'm sure I could find much more updated info supporting the asteroid impact theory, but just now I am pressed for time and I'm being lazy.
