C14 dating is NOT based on fossils, it is based on the measured half life of C14 and the fact that the C14/C12 ratios in living organisms are equal to that in the atmosphere they respire. The ratio only begins to change after death so by taking the C14/C12 ratio you can see how long something has been dead for....
This is based on the physics of nuclear decay NOT fossils...
Now the C14/C12 ratio becomes rather small after 50,000 years (around 10 half lives) so measuring a fossils age by C14 is a bit pointless...
Does that help?
™ Version 4.2