The Lomekwi Tools, and How We Maybe Almost Were Not

For a long time, the earliest tool culture was assumed to be the Oldowan, dating to about 2.6 million years ago. History is always changing, we know very little of it, and what we do know will change, but we must try anyway. One must imagine Sisyphus happy as he asserts that some particular rock was our first tool.

At current estimate, the earliest stone tools were lifted from the soil of modern-day West Turkana, Kenya. Well before we picked them up, some ancestor had found them worth carrying, knapping, and employing a staggering 3.3 million years ago.

Properly speaking, what makes the Lomekwi tools interesting is that there isn’t a “this Lomekwi tool” but rather that there are “these Lomekwi tools.” I don’t just mean that there are several of the same kind (although that’s also true – there are 149), but that there are several different varieties of tools meant to be employed together. Other primates use stones to crack nuts (and some non-primates; otters employs stone tools to extract the meat from shellfish), but the primate that used the Lomekwi tools was far more advanced.

From the paper:

The technological features of flakes and flake fragments are clear, unequivocal and seen repeatedly, demonstrating that they were intentionally knapped from the cores. They range from 19 to 205 mm long and frequently present cortex on their dorsal surfaces, sometimes on their striking platforms, or both. Three pieces in particular bear localized battered areas on their dorsal surfaces—including the specimen that refits onto the in situ core—showing that blanks were sometimes used for percussive activities before flake removal and that at least some individual blocks
were involved in several distinctively different modes of use.

The largest and heaviest (up to 15 kg) pieces in the assemblage were made on large blocks of basalt or coarse trachy-phonolite. They have flat natural surfaces that could enable their stabilization for use. Comparisons with other described anvils from the Early Stone Age and experiments suggest these can be interpreted as anvils or passive elements. Three of these show a similar wear and fracture pattern. The largest piece exhibits along one lateral plane a series of divergent step fractures
associated with crushing marks and an additional concentration of impact damage on one horizontal surface. The other two pieces have non-invasive step fractures along a greater or lesser portion of their high-angled intersecting surfaces (edges) that are associated with crushing and impact marks. A further two cobbles show heavy battering marks concentrated on a convex area and are interpreted as passive elements. Seven medium-sized cobbles display battering marks and/or impact damage associated with fractured surfaces and are interpreted as hand-held percussors or active elements.

Under the assumption that I’m reading this right, there are three proposed tools: 1) a hammerstone, known by the particular type of battering damage; 2) an anvil, the heaviest of them, known by consistent impact damage to a single flatish surface; 3) the core being knapped. In other words, this isn’t simply employing something found, nor is it quite using stone-and-anvil techniques you’d find in other animals. It’s a metalevel up, producing the tools that are then themselves directly used. In other words, a toolshop.

As a quick overview: knapping is bashing stones and/or other objects against other stones. The larger piece of stone being bashed is called the “core” (properly lithic core), and the pieces that come off of it are called “flakes” (lithic flakes). A lot of this is just called lithic reduction, for the obvious reason that the bashing process reduces the size of the core. Core and flake may both be used, and presumably a core at some point becomes a flake, i.e. the inverse of the Heap Paradox.

The researchers suggest that the tools were made using bipolar percussion and/or passive hammer technique. Bipolar percussion is when the core is placed on an anvil and hit with a hammerstone (demonstrated here, which I highly recommend watching). This would use (1-3). Passive hammer technique is simply smashing the core into the anvil (only 1 and 3).

You’ll wonder what these look like. They look like this:

source

(a-c) are the cores from which flakes were produced, while (d) is an example of the flake. As a side note, the picture is a pretty good illustration of just how much sharper flakes are even in extremely rudimentary forms.

The anvils and/or hammers look like this:

(a-b) are anvils, (c) may have been the hammerstone or not. All three exhibit wear to only one side, indicating their use for hitting (or being hit by) some other stone.

As a brief and weird side note: Oldowan culture’s tools show more sophistication, but they’re also 700,000 years later. We currently have a discontinuity for that entire period. This is almost certainly due to the recency of the Lomekwi discovery, but it may also be due to something else. As the researchers point out, we don’t really know who made the Lomekwi tools, and none of the usual candidates were actually in the area at that point:

LOM3 predates the oldest fossil specimens attributed to Homo in West Turkana at 2.34 6 0.04 Ma7 by almost a million years; the only hominin species known to have been living in the West Turkana region at the time is K. platyops27, while Australopithecus afarensis is found in the Lower Awash Valley at 3.39 Ma in association with cutmarked bones from Dikika20. The LOM3 artefacts indicate that their makers’ hand motor control must have been substantial and thus that reorganization and/or expansion of several regions of the cerebral cortex (for example, somatosensory, visual, premotor and motor cortex), cerebellum, and of the spinal tract could have occurred before 3.3 Ma. The functional morphology of the upper limb of Pliocene hominins (especially A. afarensis, the only species for which contemporaneous fossil hand and wrist elements are known), particularly in terms of adaptations for stone tool making, must be investigated further if this important milestone in human evolution is to be understood more fully.

I’m going to repeat that I’m not an academic, but theoretically, the gap in tool use might be because the tradition we inherited was passed down by members of the Homo family, whereas the makers of the Lomekwi tools died out. The researchers also suggest Kenyanthropus, which is a hominin but may or may not be in the Homo family. Scientific American elaborates on this possibility.

I find this idea kind of unnerving, as though there was once a whole alternate history prepared for Non-Homo sapiens suddenly cut short, leaving us to inherit the earth through some unjust accident.

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References

3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya – Sonia Harmand, Jason E. Lewis, et al., Nature, 2015

Archaeologists Take Wrong Turn, Find World’s Oldest Stone Tools – Kate Wong, Scientific American, 2015

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