What are actual chemical traces of protein fragments, or peptides, doing in a fossilized T. rex bone? That question led some paleontologists to reject a 2007 study claiming to have found surviving molecules of biochemicals. A reexamination, though, showed that the first report was correct. We do have traces of hemoglobin and collagen from an animal 68 million years old.
COMMENT: Any T. rex news is automatically cool.