come on. this doesn’t make any sense whatsoever. 20,000 years to work on a painting? something is wrong.
I think that the authors must have been journalism majors.
I bet what the scientists are saying is that the paintings were worked on continuously for 20,000 years.
I suspect that they were changed, refreshed, added to, subtracted from and just generally monkeyed with as the local peoples went about there lives and recorded their world on those walls for 200 centuries.
Give it time.
The sphinx has been worked on for 4500 years.