Modern humans were making sophisticated stone tools at least 71,000 years ago, according to an article in the November issue of Nature based on excavations in South Africa.
The long, thin blades were found at Pinnacle Point, which lies near Mossel Bay on the country's southern coast.
Thought to have been used for weapons, the pieces were produced using an advanced process described as "heat treatment."
The team suggests the blades were employed in spear-throwers, or "atlatls," a weapon enabling human hunters to kill large prey, such as buffalo, from a greater distance.
The discovery indicates the humans who inhabited the area more than 70 millennia ago already possessed significant cognitive abilities, the authors say.
Study co-author Kyle Brown, a skilled stone tool replicator and an honorary research associate with the University of Cape Town, said the advanced weapons technology would have been "essential" to the spread of modern humans beyond Africa.
Until now, archaeologists have seen few examples of implements of this kind dating from more than 40,000 years ago.
The authors of the article say they found evidence the humans living at Pinnacle Point continued making sophisticated tools for a span of 11,000 years.
The enduring nature of the technology points to a capability for complex thought and for passing knowledge on to the next generation, probably through the use of language, the scientists say.