Carbon 14 or 16 dating
It is calibrated by C14 dating, and the ages given by the two methods are in close agreement after such calibration.
In millions of years, there would certainly be roughly equal numbers of D and L forms, so that the ratio of D to L would be one.
Even more, proteins in this tissue retain their structure.
After an organism dies, if it is buried and left undisturbed, the C14 in it gradually decays into nitrogen 14. Thus the ratio of C 14 to C12 in the remains of the organism gradually decreases with time.
These results were discussed in a recent Mary Schweitzer’s results shows that essentially all the remaining material in the dinosaur bone is original because she had no trouble finding these young appearing proteins.
If there had been contamination, then it would have introduced other substances into the soft tissue.
Here is a discussion of this and related finds by Brian Thomas, a creation oriented author: verified and extended protein identification in a duck-bill dinosaur that Mary Schweitzer’s team had described in 2009.
These two new finds join dozens of others published over the last half-century, but evolutionary scientists still have a hard time accepting that these fossils retain original biochemicals.
Search for carbon 14 or 16 dating:
In a 2015 paper in , her group reported isolating fragments of eight other proteins from fossils of dinosaurs and extinct birds, including hemoglobin in blood, the cytoskeletal protein actin, and histones that help package DNA. All amino acids except glycine (the simplest one) are optically active, having a stereocenter at their α-C atom.