A team of researchers from the U.S. and France have discovered hand axes, cleavers and picks in Kenya that date back further than the oldest previously discovered tools. They were used by Homo Erectus about 1.76 million years ago.
Similar stone-age tools discovered in Ethiopia and Tanzania are estimated to be 1.4 to 1.6 million years old. The implication is that Homo Erectus had acquired the ability to plan and manufacture refined tools earlier than previously thought.
The simplest stone tools were made by bashing rocks together, but the newly discovered tools "required a good deal of forethought as well as dexterity to manufacture," said a scientist who was not involved in the discovery.