Oldest site for distinctive early stone tools found
Stone tools played an important role in human evolution and one of the most significant stone technologies was the Acheulean, distinguished by the tools' characteristic tear drop and oval shaped handaxes. This technology, named for the place in France where some of the first examples were found in the 19th century, was thought to have originated around 1.4 million years ago (ma).
A team working at West Turkana in Kenya reported this week in the journal Nature the discovery of a collection of Acheulean tools paleomagnetically dated to 1.76 ma and this has implications, as discussed in the abstract of the Nature article, quoted hereunder.
“The Acheulian is one of the first defined prehistoric techno-complexes and is characterized by shaped bifacial stone tools. It probably originated in Africa, spreading to Europe and Asia perhaps as early as ~1 million years (Myr) ago. The origin of the Acheulian is thought to have closely coincided with major changes in human brain evolution, allowing for further technological developments. Nonetheless, the emergence of the Acheulian remains unclear because well-dated sites older than 1.4 Myr ago are scarce. Here we report on the lithic assemblage and geological context for the Kokiselei 4 archaeological site from the Nachukui formation (West Turkana, Kenya) that bears characteristic early Acheulian tools and pushes the first appearance datum for this stone-age technology back to 1.76 Myr ago. Moreover, co-occurrence of Oldowan and Acheulian artefacts at the Kokiselei site complex indicates that the two technologies are not mutually exclusive time-successive components of an evolving cultural lineage, and suggests that the Acheulian was either imported from another location yet to be identified or originated from Oldowan hominins at this vicinity. In either case, the Acheulian did not accompany the first human dispersal from Africa despite being available at the time. This may indicate that multiple groups of hominins distinguished by separate stone-tool-making behaviours and dispersal strategies coexisted in Africa at 1.76 Myr ago.”
A thorough discussion of these new finds appeared in The New York Times on August 31.
Within a fortnight BecomingHuman.org expects to mount a video introduction to stone tool technology entitled Early Craftsmanship.