
In March, we reported on the role of mitochondrial DNA in confirming the identity of a skeleton found in a Leicestershire car park as King Richard III. There’s another analytical component to the story, involving the use of radiocarbon dating. The Oxford Radiocarbon Accelerator Unit and the Scottish Universities Environmental Research Centre (SUERC) in East Kilbride both used accelerator mass spectrometry (AMS) radiocarbon dating, each analyzing two small rib bone samples.
The findings dated the remains to AD1475-1530, consistent with them being Richard III’s. Analysis of stable carbon and nitrogen isotopes also gives information about the source of the protein that was eaten by the living individual. Derek Hamilton from SUERC explains: “δ13C gives us information about how much marine protein was in the diet. Essentially, if you only ate beef, the δ13C value of your bones would be around -21.0 per mille, but if all you ate was seal meat that value would be about -12.5 per mille. The average of the four measurements was -18.5 per mille. If we extrapolate between our two endpoints it suggests that the diet consisted of approximately 25 percent marine-derived protein.”
So, King Richard was a fan of seafood. But what kind? “δ15N, provides extra information about where in the food chain the food was derived. As you move up the food chain its number increases. Marine environments have much longer chains than on the land, so this number can also cast some light on where in the marine food chain the individual was sourcing their protein. Our results suggest that he did not only eat species that were lower in the food chain, such as oysters, crabs, and mussels, but rather that his marine protein was from a variety of sources.”
Read more about this in 'Winter of Content'.