Although the theories in these cartoons are not among them (after Gary Larson top, from http://biblische.blogspot.com/2009/12/story-of-my-life.html bottom), there are a number of alternatives to the baked-by-returning-debris-from-the-impact theory we have discussed in the main lecture. They include that the impact caused widespread climate change, that it led to a period of enhanced volcanic activity, or that climate change not related to it was the primary cause of the mass extinctions.

Image from http://www.cocs.com/imagegallerydetail.asp?ImageID=3,

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