Sharp Stone Age spearheads were cooked then flaked

"If you want to make really sharp stone spearheads, do like Stone Age cave dwellers did and cook them first.

Palaeoanthropologists have discovered that this two-step trick was invented 50,000 years earlier than they previously thought. The findings add to evidence that Africa's southern tip was a centre of technological and cultural development during the middle Stone Age."
via New Scientist / read more