The famous phrase that comes to mind concerning prehistoric life is "nasty, brutish... and short."
I am not so sure.
Just why is it mankind suffers from tooth decay?
One would think that evolution would not allow a life form to evolve with a defect--especially a defect so serious as one that affects the organism's ability to eat.
something is wrong.
And, I suspect it's diet--I suspect the people in this grave ate things they weren't evolved to eat.