Comment by mrguyorama

>Secondarily, I wouldn't think that you could apply radiocarbon dating in a meaningful way to anything that's not from pre-nuclear-testing earth.

I don't think this is relevant. For C-14 dating, the way it works is that as you are alive, you take in sources of carbon, and some well understood and modeled percentage of that carbon is a radioactive isotope. That isotope is produced when csomic rays hit the upper atmosphere, and that C14 then reacts with oxygen to make C(14)O2. Plants turn this radioactive CoO2 into other organic matter that is eaten by other things and incorporated into their body.

The moment that animal dies, C14 stops being added to their body. As C14 has a known rate of decay, you can look at the percentage of carbon in the sample that is C14, plus the decay products, and estimate how long that sample has been not alive, which for old things, correlates well with how long ago it was alive.