Early human relatives purposefully crafted stones into spheres 1.4 million years ago, study claims

Limestone spheroids from the 'Ubeidiya archaeological site in northern Israel.
Some of the limestone spheroids from the 'Ubeidiya archaeological site in northern Israel, which date back approximately 1.4 million years. (Image credit: Muller et al.)

Around 1.4 million years ago, early human relatives crafted enigmatic stone "spheroids" in the Middle East in deliberate attempts to make perfect spheres, a new study finds.

The finding shows the intention of early hominins, such as Homo erectus, to "impose" a symmetry on the stones — the oldest known evidence of such planning, the researchers suggested.

It's possible these deliberately spherical stones "conferred some sort of functional advantage over naturally rounded stones available in the landscape," study lead author Antoine Muller, an archaeologist at the Hebrew University of Jerusalem, told Live Science in an email. And "their tendency to become more spherical as they are made suggests a preference for symmetry and an appreciation of geometry."

Related: Cave thought to hold unicorn bones actually home to Neanderthal artwork

Mysterious spheroids

The study found that early hominins chipped away at the spheroids in stages so that they became more spherical over time. The researchers say this was a deliberate intention. (Image credit: Muller et al/Royal Society Open Science)

Hundreds of stone spheroids, typically made from limestone or sandstone, have been unearthed at archaeological sites in Africa, Asia and Europe. The smallest are just one inch (2.5 centimeters) across, or about the size of a walnut; most are between three inches (8 cm) and four inches (10 cm) across, or about the size of an orange. Many spheroids have been found at stone toolmaking sites, and some other studies suggest they  are well-used "hammerstones," perhaps for pounding sharp-edged flakes off other stones, or stones "cores" that flakes had been knocked from.

The earliest spheroids are up to 2 million years old. But they span the entire era of stone toolmaking, and some have been found at Neolithic and later sites that are only a few thousand years old.

Muller and his colleagues examined 150 limestone spheroids unearthed at the 'Ubeidiya archaeological site in northern Israel and dated to about 1.4 million years ago, when Homo erectus was the dominant hominin, according to the study, published Sept. 6 in the journal Royal Society Open Science.

The researchers used mathematical analysis to determine that the spherical shape of some of the objects — which range from rough polyhedrons to near spheres — was deliberate, likely worked on in stages and not accidental.

"We argue that this spherical shape was something they aimed to produce," Muller said. "The ones that were more 'finished' were more spherical, suggesting that this was one attribute they were aiming for."

Symmetry in stone

More than 150 limestone spheroids and other ancient artifacts have been unearthed at the 'Ubeidiya archaeological site in northern Israel. (Image credit: Hanay (CCA-SA 3.0))

The researchers noted that earlier studies had seen symmetry in Acheulean bifaces, a type of stone tool dating from up to 1.7 million years ago, and that this was thought to be the earliest evidence of "hominins imposing a geometric shape and symmetry on their stone tools."

But it now seems that the spheroids, which are older, may have had the same purpose — and perhaps other purposes as well.

"If symmetry was desired by knappers of Acheulean handaxes, which are symmetrical in three axes, then spheroids, symmetrical in all directions, also fulfil this need," the researchers wrote.

Muller said the study suggested that early hominins like Homo erectus and the even earlier Homo habilis may have been more cognitively advanced than previously suspected.

"Our findings suggest that the people who made these spheroids could envisage something as abstract as a sphere and impose that conception in reality by shaping a stone," he said. "That likely takes a great deal of forethought and manual dexterity, speaking to their remarkable cognitive and skilful abilities."

Bruce Hardy, a paleoanthropologist at Kenyon College in Ohio who was not involved in the study, said the spheroids may have had an unknown practical purpose that explained their shape.

"One long-standing idea is that these were hammerstones used to knock flakes off a core," he told Live Science. "And if you just keep doing that while rotating the hammerstone around, you're going to end up with something approximating a sphere."

Hardy acknowledged that the new study showed the spheroids became mathematically more spherical as they were worked on, but he said that was not hard evidence that early hominins had deliberately shaped them.

"I think they're capable of it, but I don't know that this analysis really shows that this is what they're doing," he said.

Live Science Contributor

Tom Metcalfe is a freelance journalist and regular Live Science contributor who is based in London in the United Kingdom. Tom writes mainly about science, space, archaeology, the Earth and the oceans. He has also written for the BBC, NBC News, National Geographic, Scientific American, Air & Space, and many others.

  • FirstCrusader 1
    admin said:
    The stone spheres were crafted by early hominins who were trying to create symmetry in the objects, a new study suggests.

    Early human relatives purposefully crafted stones into spheres 1.4 million years ago, study claims : Read more
    In the history of ancient human-carved
    stone spheres worldwide, I believe that one answer to the existence/original purpose of the spheres has been ignored. I propose that there are multiple reasons for the spheres but two main ones of which one has been totally ignored - that of territoriality.
    In my view the most finished spheres and the largest spheres were used as territorial markers. I further propose that a spoken world-wide culture existed until a few thousand years ago and the use of the spheres for the purposes of marking territory was universal across the world.
    A perfect example of this idea is the huge stone sphere found in Israel some years ago buried in many feet of ground. This sphere could have marked the limits between the modern humans and Neanderthals or their partial descendants as a visible border. It stood untouched for thousands of years performing that duty, gradually being buried by the deposits created over time that raised the ground level but unmoved by anyone as a sacred boundary not to be violated. In time with movements of people's, invasions the original purpose was forgotten and the sphere buried over time.
    With the massive movements of people in the last several thousand years traditional knowledge related to specific geographic
    areas was lost so that the reasons for the spheres was lost too as were the histories of the regions and it's peoples.
  • Daniel+
    In Uruguay, Argentina and southern Brazil there are thousands of stone spheres of indigenous origin, between 500 and 15,000 years old. They are called boleadoras, and were used for hunting and fighting, tied in the amount of three by leather or fiber ribbons. They are almost perfectly spherical and their diameter varies between 5 and 10 centimeters. They have a groove in their largest diameter to be tied. There are examples in all the museums of these countries.
  • CRSmith
    Maybe they were bowling balls. I saw that once on the Flintstones.
  • Hartmann352
    Ah, the round balls from a million years ago.

    An analysis of 150 round, baseball-sized stones found at a site where early humans lived 1.4 million years ago shows that they were intentionally knapped into spheres. This rules out the idea that they became round after being used as hammers, but doesn’t tell us why they were shaped.

    “Unfortunately, we still can’t be confident about what they were used for,” says Antoine Muller at the Hebrew University of Jerusalem.

    Signs of ancient occupation at ‘Ubeidiya, in what is now northern Israel, were discovered in 1959. A few human bones and thousands of stone tools have been uncovered there. The site is thought to have been used by some of the first members of our ancestor species Homo erectus to move out of Africa.

    The finds include nearly 600 stone balls made of flint, basalt and limestone. Similar discoveries have been made at many other early human sites dating as far back as 1.8 million years ago. The objects, known as spheroids, were made by knapping, but why this was done remains a mystery.

    It has been suggested that they are a byproduct of the creation of other stone tools, or that they are stones deployed as hammers that became round as they were used rather than being deliberately shaped.

    To test this idea, Muller and his colleagues scanned 150 limestone spheroids from ‘Ubeidiya, which are of varying degrees of roundness and around 8 centimetres in diameter, roughly the size of a baseball. They worked out the sequence of strikes responsible for each ball’s shape.

    The researchers conclude that these spheroids required similar levels of skill and planning to make as hand axes, rather than being accidental creations. But the team can’t say if the same is true of any other spheroids, says Muller.

    “Clearly, whoever made these objects was working hard to make them spheres,” says Andrew Wilson at Leeds Beckett University, UK, who in 2016 showed that the shape and weight of typical spheroids are suitable for throwing.

    “To my mind, this certainly looks more like they were crafting projectiles than, say, hammers,” says Wilson. “I know from my work that these rocks would make good hunting weapons for a group of humans.”

    See: Royal Society Open Science DOI: 10.1098/rsos.230671
    Archaeologists have long debated exactly how the tennis ball-sized “spheroids” were created. Did early hominins intentionally chip away at them with the aim of crafting a perfect sphere, or were they merely the accidental byproduct of repeatedly smashing the stones like ancient hammers? Research led by the Hebrew University of Jerusalem suggests our ancestors knew what they were doing. The team of scientists examined 150 limestone spheroids dating from 1.4m years ago that were found at the ’Ubeidiya archaeological site in the north of modern-day Israel. Using 3D analysis to reconstruct the geometry of the stones, the researchers determined that their sphericalness was “likely to have been produced intentionally”.