Thousands of stone tools uncovered in a lake basin in Botswana are providing information about possible migration routes and hunting practices of early humans in the Middle and Late Stone Age periods, between 150,000 and 10,000 years ago. The research was prompted by the discovery of the first of what are believed to be the world’s largest stone tools on the bed of the lake. Although the first find was made in the 1990s, the discovery of four giant axes has not been scientifically reported until now. Four giant stone hand axes, measuring over 30 cm long and of uncertain age, were recovered from the lake basin. Link.