Tag: paranthropoids

The hand of Paranthropus boisei

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One of the longest-lived hominin species that we know of was Paranthropus boisei, remains of which occur in East African sediments between 2.6 and 1.3 Ma. Others, including our own species, lasted nowhere near as long, except perhaps for Homo erectus who emerged around 1.9 Ma ago and is believed by some to have lingered on in Java until about 112 ka ago. However, when the unresolved muddle in the Middle Pleistocene of similar-looking hominin fossils is eventually unravelled – as now seems to be on the cards – that may limit the range of H. erectus to 1.9 -1.0 Ma. Paranthropoid remains are easily distinguished from those of their contemporary hominins – australopithecines and early species of Homo – being extremely robust compared with the ‘gracile’ members of the human line. They were also bipedal, but their fossil skulls are distinctive: massive teeth and jaws, and a bone crest on top of the cranium to which very powerful chewing muscles were attached. Once regarded as a sort of upright gorilla with vegetarian habits, evidence has accumulated since their first discovery that they may have been far more remarkable.

Reconstruction of a Paranthropus head (Credit: Jerry Humphrey, Pinterest)

The earliest paranthropoid was P. aethiopicus from Ethiopia, dated at around 2.7 to 2.3 Ma, and believed to be the common ancestor of P. boisei and P. robustus found in Tanzania and South Africa respectively. Stone and bone tools associated with paranthropoid remains have been found in South and East Africa, some of which show signs of having been burnt. The connection between paranthropoids and both tool- and fire-making is clearly impossible to verify with certainty, and so too for their known association with australopithecine remains – or even the earliest known humans (Homo habilis) for that matter. Palaeoanthropologists are not likely to find a near-complete skeleton of any of these candidates with a tool grasped in the remains of a hand! The issue can be partly resolved if it can be shown that a fossil hand was capable of making and using tools. The fabled ‘opposable thumb’ that is capable of touching the tips of all four fingers is essential for the necessary ‘precision grip’. Isolated, 2 Ma-old thumb bones probably able to do that were found in the famous Swartkrans Cave in South Africa, but with no clue as to which hominin species had yielded them. In fact had that matter been resolved there and then, it would be not take the hominin story very far, simply because evidence for tool use – tools and cut marks on bone – goes back as far as 3.3 Ma, again with more than one candidate for the usefully endowed hominin species.

The left hand of Paranthropus boisei reconstructed from individual bones, palm-up on the left, palm down on the right. Credit: Mongle et al, Fig 3.

Remarkably, a group of scientists from the US, Canada, Australia, South Africa and Kenya have indeed unearthed from 1.5 Ma sediments on the shore of Lake Turkana in Kenya a near-complete left hand associated with cranial bones and teeth from Paranthropus boisei  (Mongle,C.S. and 29 others 2025. New fossils reveal the hand of Paranthropus boisei. Nature v. 647, p. 944–951; DOI: 10.1038/s41586-025-09594-8). It is clear that the P. boisei hand shared some of the manipulative capacity of modern human hands, though it bears some resemblance to gorilla hands. That hand was probably nimble enough to make and use simple stone tools. It would also have had a powerful grip, sufficient for climbing and wielding a large stick. Yet again, it does not indicate which species first adopted tool making and use.

There are several interesting possibilities. It may be that a form of convergent evolution enabled two separate genera to become capable of such skills and the intellect to put them to use: tools, however simple, confer enormous evolutionary advantages. Had the antecedents of humans – presumably a species of Australopithecus – been the first, paranthropoids may have observed and adopted tools or vice versa. Just as possible, the – as yet unknown – common ancestor of both may have made this fundamental leap, which would have benefitted both vegetarian and omnivorous descendants. In that case the physiology of each group may have diverged with their lifestyles. Eating roots and leaves requires considerably more physical effort than getting sufficient protein and fats partly by devouring flesh.

Bone tools widened hominins foraging options 1.5 Ma ago

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Hominins have been making and using stone tools since at least 3.4 Ma, as shown by cut marks on bones and stone artefacts themselves. I use the sack term ‘hominin’ because the likely makers and users of the oldest tools are either australopithecines or paranthropoids, there being no fossils designates to the genus Homo of late-Pliocene age. So it might seem  un-newsworthy to report that the oldest tools deliberately made from bone are now known to occur in 1.5 Ma old sediments from the famous sedimentary sequence at Olduvai Gorge in Tanzania (de la Torre, I and 8 others2025. Systematic bone tool production at 1.5 million years ago. Nature, v. 639; DOI: 10.1038/s41586-025-08652-5). To be clear, there is abundant evidence that hominins had used bones, especially sturdy long bones, for digging perhaps, much earlier in hominin history. Again, paranthropoids have been implicated in their use. The bones found at Olduvai actually show signs of manufacture into useful objects prior to their use: they show clear signs of knapping to produce points and blades. The bones are among the sturdiest known from the Pleistocene, being from elephants and hippos. Before de la Torre and colleagues found what is essentially a bone-tool factory, it was thought that systematic use of bones in such a sophisticated manner only arose between 400 to 250 ka ago among early Homo in Europe. Sadly, fossils of whoever made the tools were not found at the site. Once again, paranthropoids as well as early Homo  are known to have cohabited the area at that time.

‘Front, back and side’ views of a 1.5 Ma old tool made from an elephant humerus – its upper foreleg. The scale bar represents 5 cm. (Credit: de la Torre et al.; Fig 3a)

Bifacial Acheulean stone artefacts first appear in the rock record about 300 ka before these bone tools were made. So one idea that the authors put forward is that the same kind of stone knapping technique was transferred to the more abundant massive bones of the East African Pleistocene megafauna (in the absence or rarity of suitable blocks of stone?). But it remains unclear whether or not such tools were simply selected from very large bones smashed to get at their nutritious marrow. The first possibility implies a cultural shift, whereas the latter points simply to expedience. The authors are at pains to point out that the curious million-year gap in the record of bone tools may be ascribed either to the disappearance of bone technology or simply to archaeologists who worked elsewhere having not regarding bone fragments as the products of skills. That applies equally to earlier times, when bones were indeed used, though with not so much in the way of a ‘mental template’. As de la Torre et al. conclude ‘Future research needs to investigate whether similar bone tools were already produced in earlier times, persisted during the Acheulean and eventually evolved into Middle Pleistocene bone bifaces similar in shape, size and technology to their stone counterparts’.

Hominin footprints in Kenya confirm two species occupied the same ecosystem the same time

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For the last forty thousand years anatomically modern humans have been the only primates living on Planet Earth with a sophisticated culture; i.e. using tools, fire, language, art etcetera. Since Homo sapiens emerged some 300 ka ago, they joined at least two other groups of humans – Neanderthals and Denisovans – and not only shared Eurasia with them, but interbred as well. In fact no hominin group has been truly alone since Pliocene times, which began 5.3 Ma ago. Sometimes up to half a dozen species occupied the habitable areas of Africa. Yet we can never be sure whether or not they bumped into one another. Dates for fossils are generally imprecise; give or take a few thousand years. The evidence is merely that sedimentary strata of roughly the same age in various places have yielded fossils of several hominins, but that co-occupation has never been proved in a single stratum in the same place: until now.

Footprints from Koobi Fora: left – right foot of H. erectus; right – left foot of Paranthropus boisei. Credit: Kevin Hatala. Chatham University

The Koobi Fora area near modern Lake Turkana has been an important, go-to site, courtesy of the Leakey palaeoanthropology dynasty (Louis and Mary, their son and daughter-in-law Richard and Meave, and granddaughter Louise). They discovered five hominin species there dating from 4.2 to 1.4 Ma. So there was a chance that this rich area might prove that two of the species were close neighbours in both space and time. In 2021 Kenyan members of the Turkana Basin Institute based in Nairobi spotted a trackway of human footprints on a bedding surface of sediments that had been deposited about 1.5 Ma ago. Reminiscent of the famous, 2 million years older Laetoli trackway of Australopithecus afarensis in Tanzania, that at Koobi Fora is scientifically just as exciting  for it shows footprints of two hominin species Homo erectus and Paranthropus boisei who had walked through wet mud a few centimetres below the surface of Lake Turkana’s ancient predecessor (Hatala, K.G. and 13 others, 2024. Footprint evidence for locomotive diversity and shared habitats among early Pleistocene hominins. Science, v. 386, p. 1004-1010; DOI: 10.1126/science.ado5275). The trackway is littered with the footprints of large birds and contains evidence of zebra.

One set of prints attributed to H. erectus suggest the heels struck the surface first, then the feet rolled forwards before pushing off with the soles: little different from our own, unshod footprints in mud. They are attributed to H. erectus. The others also show a bipedal gait, but different locomotion. The feet that made them were significantly flatter than ours and had a big toe angled away from the smaller toes. They are so different that no close human relative could have made them. The local fossil record includes paranthropoids (Paranthropus boisei), whose fossil foot bones suggest an individual of that speciesmade those prints. It also turns out that a similar, dual walkers’ pattern was found 40 km away in lake sediments of roughly the same age. The two species cohabited the same terrain for a substantial period of time. As regards the Koobi Fora trackway, it seems the two hominins plodded through the mud only a few hours apart at most: they were neighbours.

Artists’ reconstructions of: left – H. erectus; right – Paranthropus boisei. Credits: Yale University, Roman Yevseyev respectively

From their respective anatomies they were very different. Homo erectus was, apart from having massive brow ridges, similar to us. Paranthropus boisei had huge jaws and facial muscles attached to a bony skull crest. So how did they get along? The first was probably omnivorous and actively hunted or scavenged meaty prey: a bifacial axe-wielding hunter-gatherer. Paranthropoids seem to have sought and eaten only vegetable victuals, and some sites preserve bone digging sticks. They were not in competition for foodstuffs and there was no reason for mutual intolerance. Yet they were physically so different that intimate social relations were pretty unlikely. Also their brain sizes were very different, that of P. Boisei’s being far smaller than that of H. erectus , which may not have encouraged intellectual discourse. Both persist in the fossil record for a million years or more. Modern humans, Neanderthals and Denisovans, as we know, sometimes got along swimmingly, possibly because they were cognitively very similar and not so different physically.

Since many hominin fossils are associated with riverine and lake-side environments, it is surprising that more trackways than those of Laetoli and Koobi Fora have been found. Perhaps that is because palaeoanthropologists are generally bent on finding bones and tools! Yet trackways show in a very graphic way how animals behave and interrelate with their environment, for example dinosaurs. Now anthropologists have learned how to spot footprint trace fossils that will change, and enrich the human story.

See also: Ashworth, J. Fossil footprints of different ancient humans found together for the first time. Natural History Museum News 28 November 2024; Marshall, M. Ancient footprints show how early human species lived side by side. New Scientist, 28 November 2024