See some of the comments in the link. I like the one best that points out that a 6 foot long burrowing dinosaur was a lot larger than our own rat sized ancestors. Probably had a really hard time finding enough food after a worldwide disaster, especially if it was warm blooded.
Good point. We already have the K-T layer smoking gun so the asteroid impact is without a doubt.
What may be in doubt is if there is any other contributor and how long some of the dinosaurs survived. It could be that the asteroid had some other lasting effect on the earth, even causing a minor shift in orbit or tilt that helped do away with the tougher dinosaurs.
