The Earliest Stone Tools
The earliest stone tools consciously made by humans were pebbles that were chipped on one side producing a core with a sharp cutting edge and flakes that could be used for a variety of purposes.
The oldest known chopping tools were found in the Olduvai Gorge in Tanzania which is part of the Rift Valley, a 100 mile long tear in the Earth's crust in East Africa. They were found next to animal bones and were probably used to strip the meat from these bones and crush them to access the nutritious marrow.
The first Oldowan choppers were discovered by Louis Leaky in the 1930s. and are thought to be almost 2 million years old. It is not known for sure who produced and used these tools but they have been associated with Australopithicine and Homo species such as Homo habilis and Homo ergaster. The chopper technology was inherited by early Homo erectus, spreading this technology all over Europe and Asia and later refining it into the bifacial handaxe industry.
The early homonids using these pebble tools are thought to have been opportunistic scavengers rather than active hunters, who waited their chance to move in with their choppers to access the meat and marrow after the top level predators, such as lions and leopards, had killed their prey. These chopping tools, simple as they may look, are quite versatile implements and may also have been used to strip the bark of trees or to dig for and peel roots. The availability of meat and highly nutritious marrow not only fed the body but also fuelled the power-hungry mind and may have jump-started the evolution of a larger brain capable of making even more complex tools.
Shown here is a European example of a unifacial pebble chopper made on a river-worn quartzite pebble (L=10cm, W=8cm (bottom) 5cm (tip), T=3.5cm). This chopper was found on the high gravel terraces of the Guadalquivir river in Southern Spain. Similar pebble tools have been found in North Africa, near Casablanca in Morocco (for further reading see: Aggsbach's Palaeolithic blog), which could indicate that early pebble culture homonids may have used the Strait of Gibraltar landbridge to access the European continent.
Although some care must be taken with interpreting pebble tool finds, some of which appear to be pseudo-artifacts generated by high-energy deposits, this specimen shows clear hallmarks of alternate flake removal on three edges of the same face. The other face of the cobble shows the smooth naturally water-worn surface that was used to hold it.
To make use of the cutting surface of this specific pebble tool it can only be held in the left hand, as shown here. Interestingly, early stone tools (1.9 - 1.4 million years ago) show an almost equal right-hand left-hand ratio compared to modern humans where this ratio is 9:1. This dramatic change in handedness may be the result of evolving brain function and the development of speech, a specialisation that is seated in the left hemisphere of the brain in most people.
Check out this recent video on the Olduvai tools and their makers:
