“ Mastodons — a 6-ton distant cousin to modern-day elephants — went extinct in North America around 10,500 years ago, likely due to climate change and hunting.”
It was all of those cars being driven around back then
He was probably running for it, because Fred Flintstone was taking his family to the take-out joint.
If no cuts or stone tool traces are fount with the remains, then I vote for this animal being a victim of the meteor strike(s) recorded in the book at comment 2. A lot of animals and humans probably died back then, but it took another 3,000 years for this type of elephants to finish dying off in North America.