[wyattearp]

Naw, the dinosaurs got roasted ~ mammals and birds who burrowed "survived". Oxygen levels remained pretty much the same.

Um. No. Wrong on the Oxygen levels:

(Oxygen level in Mesozoic)

Where is the evidence of roasted dinosaurs? (Hint: there isn't any).

[muawiyah]

The oxygen level materials that you reference are highly speculative. We know they were far higher in earlier periods, but so was carbon dioxide.