Innovative Stone Age tools may have been developed by people in Eurasia and -- contrary to widely held views -- not just invented in Africa, a new study suggests.
Research published in the journal Science, shows evidence that refined stone weapons were developed in Armenia about 325,000 years ago.
The find challenges the theory held by many archaeologists that sophisticated stone tool technology came from Africa then spread to Eurasia as the human population expanded.
Experts studied thousands of stone artifacts from the Nor Geghi site in Armenia, which sits between two lava flows dated between 200,000 and 400,000 years old.
"The discovery of thousands of stone artifacts preserved at this unique site provides a major new insight into how Stone Age tools developed during a period of profound human behavioral and biological change," said Simon Blockley of the University of London.
"Due to our ability to accurately date the site in Armenia, we now have the first clear evidence that this significant development in human innovation occurred independently within different populations," said Blockely.
Analysis of volcanic ash and sediment at the site indicated the artifacts were between 325,000 and 335,000 years old. The tools were crafted using two different technologies.
Bifacal technology, used to produce axes during the Lower Palaeolithic, involves chipping away at a mass of stone until the desired shaped is formed. The chips are discarded.
The more sophisticated Levallois technology is where a stone is carved into a convex shape and used as a knife or other sharp object. The discarded flakes are used to produce small tools such as sharp points.
The latter technique appears in the archaeological record across Eurasia between 200 to 300,000 years ago during the Middle Paleolithic period, and earlier in Africa during the Middle Stone Age.
The presence of the two technologies at the site in Armenia provides the first clear evidence that local populations developed Levallois technology out of existing biface technology, argue the researchers.
"The combination of these different technologies in one place suggests to us that, about 325,000 years ago, people at the site were very innovative," said the study's lead author Associate Professor Daniel Adler of the University of Connecticut.
In addition to this, chemical analysis of several hundred of the artifacts made from obsidian shows that humans sourced the stones from outcrops up to 75 miles away.
"The procurement of obsidian from a variety of local and nonlocal sources suggests that hominins [at this site] were exploiting large, environmentally diverse territories," report the researchers.
Rather than a "technical breakthrough" that spread from a single point of origin, the evolution of Levallois technology was gradual and intermittent and occurred within different human populations that share a common technological ancestry, they argue.
-- AFP contributed to this report.