“This site reveals an extraordinary story of cultural continuity,” said Braun in a recent press release.
When the going gets tough, the tough make tools
Nomorotukunan’s layers of stone tools span the transition from the Pliocene to the Pleistocene, during which Earth’s climate turned gradually cooler and drier after a 2 to 3 million-year warm spell. Pollen and other microscopic traces of plants in the sediment at Nomorotukunan tell the tale: the lakeshore marsh gradually dried up, giving way to arid grassland dotted with shrubs. On a shorter timescale, hominins at Nomorotukunan faced wildfires (based on microcharcoal in the sediments), droughts, and rivers drying up or changing course.
“As vegetation shifted, the toolmaking remained steady,” said National University of Kenya archaeologist Rahab N. Kinyanjui in a recent press release. “This is resilience.”
Making sharp stone tools may have helped generations of hominins survive their changing, drying world. In the warm, humid Pliocene, finding food would have been relatively easy, but as conditions got tougher, hominins probably had to scavenge or dig for their meals. At least one animal bone at Nomorotukunan bears cut marks where long-ago hominins carved up the carcass for meat—something our lineage isn’t really equipped to do with its bare hands and teeth. Tools also would have enabled early hominins to dig up and cut tubers or roots.
It’s fair to assume that sharpened wood sticks probably also played a role in that particular work, but wood doesn’t tend to last as long as stone in the archaeological record, so we can’t say for sure. What is certain are the stone tools and cut bones, which hint at what Utrecht University archaeologist Dan Rolier, a coauthor of the paper, calls “one of our oldest habits: using technology to steady ourselves against change.”
A tale as old as time
Nomorotukunan may hint that Oldowan technology is even older than the earliest tools archaeologists have unearthed so far. The oldest tools unearthed from the deepest layer at Nomorotukunan are the work of skilled flint-knappers who understood where to strike a stone, and at exactly which angle, to flake off the right shape. They also clearly knew how to select the right stones for the job (fine-grained chalcedony for the win, in this case). In other words, these tools weren’t the work of a bunch of hominins who were just figuring out, for the first time, how to bang the rocks together.
“The combination of shaping, wear, and resharpening indicates they were used to draw or mark on soft surfaces,” D’Errico told Ars in an email. “Although the material is too fragile to reveal the specific material on which they were used, such as hide, human skin, or stone, an experimental approach may, in the future, allow us at least to rule out their use on some materials.”
A 73,000-year-old drawing from Blombo Cave in South Africa looks like it was made with tools much like the ocher crayons from Crimea, which means that Neanderthals and Homo sapiens both invented crayons in their own little corners of the world at around the same time.
The surface of this flat piece of orange ocher was carved over 47,000 years ago, then worn smooth, perhaps by carrying in a bag. Credit: D’Errico et al. 2025
Sometimes you’re the crayon, sometimes you’re the canvas
A third item from Zaskalnaya V is a flat piece of orange ocher. One side is covered with a thin layer of hard, dark rock. But more than 47,000 years ago, someone carefully cut several deep lines, regularly spaced and almost parallel, into its surface. The area of stone between the lines has been worn and polished smooth, suggesting that someone carried it and handled it for years.
“The polish smoothing the engraved lines suggest that the piece was curated, perhaps transported in a bag,” D’Errico told Ars. Whoever carved the lines into the piece of ocher also appears to have been right-handed, based on the angle of the incisions’ walls.
“Traditionally viewed as lacking the cognitive flexibility and symbolic capacity of humans, the Neanderthals of Crimea demonstrate the opposite: They engaged in cultural practices that were not merely adaptive but deeply meaningful,” wrote D’Errico and his colleagues. “Their sophisticated use of ocher is one facet of their complex cultural life.”
The tip of this red ocher crayon was broken off. Credit: D’Errico et al. 2025
Coloring in some details of Neanderthal culture
It’s hard to say whether the rest of the ocher from the Zaskalnaya sites and other nearby rock shelters meant anything to the Neanderthals beyond the purely pragmatic. However, it’s unlikely that humans (of any stripe) could spend 70,000 years working with vividly colored pigment without developing a sense of aesthetics, assigning some meaning to the colors, or maybe doing both.
Some stone tools found near a river on the Indonesian island of Sulawesi suggest that the first hominins had reached the islands by at least 1.04 million years ago. That’s around the same time that the ancestors of the infamously diminutive “Hobbits” may have reached the island of Flores.
Archaeologist Budianto Hakim of Indonesia’s National Research and Innovation Agency and his colleagues were the ones who recently unearthed the tools from a site on Sulawesi. Although a handful of stone flakes from that island don’t tell us who the ancestors of the small species were or how they reached remote islands like Flores and Luzon, the tools are one more piece in the puzzle. And this handful of stone flakes may eventually play a role in helping us understand how other hominin species conquered most of the world long before we came along.
Crossing the ocean a million years ago
Sometimes the deep past leaves the smallest traces. At the Calio site, a sandstone outcrop in what’s now a cornfield outside the village of Ujung in southern Sulawesi, people left behind just a handful of sharp stone flakes roughly a million years ago. There are seven of them, ranging from 22 to 60 millimeters long, and they’re scratched, worn, and chipped from tumbling around at the bottom of a river. But it’s still clear that they were once shaped by skilled human—or at least human-like—hands that used hard stones as hammers to make sharp-edged chert flakes for cutting and scraping.
The oldest of these tools is likely to be between 1.04 and 1.48 million years old. Hakim and his colleagues dated teeth from a wild pig to around 1.26 million years ago. They were part of a jawbone archaeologists unearthed from a layer just above the oldest flake. Throw in some statistical modeling, and you get the range of likely dates for the stone flake buried in the deepest layer of soil.
Even the younger end of that estimate would make these tools the oldest evidence yet of hominins (of any species) in the islands of Indonesia and the Philippines. This area, sometimes called Wallacea, lies between the continents of Asia and Australia, separated from both by wide channels of deep ocean.
“But the Calio site has yet to yield any hominin fossils,” said Brumm, “so while we now know there were tool-makers on Sulawesi a million years ago, their identity remains a mystery.” But they may be related to the Hobbits, a short-statured group of hominins who lived hundreds of kilometers away on the island of Flores until around 50,000 years ago.
“The discovery of Early Pleistocene artifacts at Calio suggests that Sulawesi was populated by hominins at around the same time as Flores, if not earlier,” wrote Hakim and his colleagues in their recent paper.
The Flores connection
The islands that now make up Indonesia and the Philippines have been a hominin hotspot for at least a million years. Our species wandered onto the scene sometime between 63,000 and 73,000 years ago, but at least one other hominin species had already been there for at least a million years. We’re just not sure exactly who they were, when they arrived, or how.
“Precisely when hominins first crossed to Sulawesi remains an open question, as does the taxonomic affinity of the colonizing population,” the authors note.
This map shows the islands of Wallacea. The large one just east of Java is Sulawesi. Credit: Darren O’Connell
That’s why the handful of stone tools the team recently unearthed at Calio matter: They’re another piece of that puzzle, albeit a small one. Every slightly older date is one step closer to the first hominin tools, bones, or footprints in these islands, and another pin on the map of who was where and when.
And that map is accumulating quite a lot of pins, representing an ever-increasing number of species. Once the first hominins made it across the Makassar Strait, they found themselves in isolated groups on islands cut off from the mainland—and each other—so the hominin family tree started branching very quickly. On at least two islands, Flores and Luzon, those original hominin settlers eventually gave rise to local species, Homo floresiensis and Homo luzonensis. And University of Wollongong paleoanthropologist Richard Roberts, a co-discoverer of Homo floresiensis, thinks there are probably more isolated island hominin species.
In 2019, when Homoluzonensis was first described, Roberts told Ars, “These new fossils, and the assignation of them to a new species (Homo luzonensis), fulfills one of the predictions Mike Morwood and others (myself included) made when we first reported (15 years ago!) the discovery of Homo floresiensis: that other unknown species of hominins would be found in the islands of Southeast Asia.”
Both Homo floresiensis (the original “Hobbits”) and Homo luzonensis were short, clocking in at just over a meter tall. Their bones and teeth are different enough from each other to set them apart as a unique species, but they have enough in common that they probably share a common ancestor—one they don’t share with us. They’re more like our distant cousins, and the islands of Wallacea may have been home to many other such cousins, if Roberts and his colleagues are correct.
Complicated family history
But who was the common ancestor of all these hominin cousins? That’s where things get complicated (as if they weren’t already). Most paleoanthropologists lean toward Homo erectus, but there’s a chance—along with some tantalizing hints, and no direct evidence—that much more ancient human relatives called Australopithecines may have made the journey a million (or two) years before Homo erectus.
Finger and toe bones from Homo luzonensis are curved, as if they spent as much of their lives climbing trees as walking. That’s more like Australopithecines than any member of our genus Homo. But their teeth are smaller and shaped more like ours. Anthropologists call this mix of features a mosaic, and it can make it tough to figure out how hominin species are related. That’s part of why the question of when the ancestors of the Hobbits arrived on their respective islands is so important.
Compare the teeth and phalanx of Homo luzonensis to those of Homo sapiens (right) and Australopithecus afarensis (left). Credit: Tocheri 2019
We don’t know the answer yet, but we do know that someone was making stone tools on Flores by 1.02 million years ago. Those toolmakers may have been Homo erectus, Australopithecines, or something already recognizable as tiny Homo floresiensis. The Hobbits (or their ancestors) were distinctly “Hobbity” by around 700,000 years ago; fossil teeth and bones from a handful of hominins at a site called Mata Menge make that clear. The Hobbits discovered at Liang Bua Cave on Flores date to somewhere between 50,000 and 100,000 years ago.
Meanwhile, 2,800 kilometers away on the island of Luzon, the oldest stone tools, along with their obvious cut marks left behind on animal bones, date back to 700,000 years ago. That’s as old as the Mata Menge Hobbits on Flores. The oldest Homo luzonensis fossils are between 50,000 and 67,000 years old. It’s entirely possible that older evidence, of the island’s original settlers and of Homo luzonensis, may eventually be found, but until then, we’re left with a lot of blank space and a lot of questions.
And now we know that the oldest traces of hominin presence on Sulawesi is at least 1.04 million years old. But might Sulawesi have its own diminutive hominins?
So are there more Hobbits out there?
“Sulawesi is a wild card—it’s like a mini-continent in itself,” said Brumm. “If hominins were cut off on this huge and ecologically rich island for a million years, would they have undergone the same evolutionary changes as the Flores hobbits? Or would something totally different have happened?”
Reconstruction of Homo floresiensis by Atelier Elisabeth Daynes. Credit: Kinez Riza
A phenomenon called island dwarfism played a role in Homo floresiensis‘ evolution; species that live in relative isolation on small islands tend to evolve into either much larger or much smaller versions of their ancestors (which is why the Hobbits shared their island home with pygmy elephants and giant moas). But how small does an island need to be before island dwarfism kicks in? Sulawesi is about 12 times as large as Flores, for example. So what might the descendants of the Calio toolmakers have looked like by 100,000 years ago?
That’s something that we’ll only know if archaeologists on Sulawesi, like Hakim and his team, find fossil remains of those hominins.
Seafarers or tsunami survivors?
Understanding exactly when hominins first set foot on the island of Sulawesi might eventually help us figure out how they got there. These islands are thousands of kilometers from the Southeast Asian mainland and from each other, so getting there would have meant crossing vast stretches of deep, open ocean.
Archaeologists haven’t found any evidence that anyone who came before our species built boats or rafts, although those watercraft would have been made of materials that tend to decay pretty quickly, so even scraps of ancient wood and rope are extremely rare and lucky finds. But some ancient hominins did have a decent grasp of all the basic skills they’d need for at least a simple raft: woodworking and rope-making.
Another possibility is that hominins living on the coast of mainland Southeast Asia could have been swept out to sea by a tsunami, and some of them could have been lucky enough to survive the misadventure and wash ashore someplace like Sulawesi, Flores, or Luzon (RIP to any others). But for that scenario to work, enough hominins would have had to reach each island to create a lasting population, and it probably had to happen more than once to end up with hominin groups on at least three distant islands.
Either way, it’s no small feat, even for a Hobbit with small feet.
