What Neanderthals really looked like – and the twins bringing them back to life

Alfons and Adrie Kennis have devoted their lives to creating models of our ancient relatives – sometimes with controversial results

Like a treasure hunter with an oddity from some distant land, Adrie Kennis squints curiously at his model of an ancient woman’s skull. It must be the hundredth time he has seen her – she lives on his shelf, at his studio in the quiet Dutch city of Arnhem – and yet he could not be more excited to hold her in his hands.
“She has a robust face,” says Adrie, which is “not typically what you expect from a female”. Where others would see a gaping hole below her eyes, Adrie sees ‘a very big, tall, broad nose’. From across the room, Adrie’s twin brother, Alfons, points out the woman’s worn-down teeth, which she would have used ‘like a vice’ to chew leather. It prompts Adrie to bite down on four of his fingers and make a loud gnawing sound.
The woman, known as Shanidar Z, is a 75,000-year-old female Neanderthal found at the Shanidar Cave in Iraqi Kurdistan, in 2018. When archaeologist Dr Emma Pomeroy and her University of Cambridge-led team stumbled upon her, she was curled up in a hollowed-out gully, as if tucked in for a nap. The way she was laid to rest would have been the decision of the woman’s family, who archaeologists believe returned to the cave, cooking and sleeping near to her body.
By the time she was found, Shanidar Z’s bones had become “like biscuits dunked in tea”, Pomeroy says. Her skull had been flattened out into a couple of centimetres of sediment, smashed into more than 200 tiny pieces by a rockfall. The team faithfully scooped out the fragments, along with the sediment that they lay in, holding them together, and flew them back to the Cambridge lab.
It then took eight months for lead conservator Dr Lucía López-Polín to put the pieces back together into a skull with “only a few deformities”. She describes the process as like finishing “a very fragile jigsaw, where you can’t see the edges of each piece”.
The team scanned the skull and sent the resulting data over to the Kennis twins, who downloaded her digital form on to their 3D printer. From there the pair got to work on making a lifelike reconstruction of the woman. They laid modelling clay on to the skull, forming muscles and then skin, before taking a mould. Then layers of flesh-like silicone were artfully applied, to reveal “a nice, elegant face, with some peace on it”, Alfons says.
Genetic material scraped from Shanidar Z’s fascinating teeth threw up a surprise. “When I got the skull, I thought I had to make a male, with all these rough features,” Adrie says, using a model of a male Neanderthal found in the same cave in 1957 to show their similarities.
“Then after the [material was sequenced] I got the call asking what I think the gender is.” The pair were sworn to secrecy until Shanidar Z’s debut in the Netflix documentary for which their model was commissioned, called Secrets of the Neanderthals, which came out in May.
The woman has now joined the cast of characters that line the brothers’ studio. It is a catalogue of all of human evolution: a clay cast of Shanidar Z sits next to the smiling faces of one of Europe’s earliest Homo sapiens, around 34,000 years old, found in the Peștera cu Oase (meaning cave with bones) in Romania, and Cheddar Man, Britain’s oldest almost-complete Homo sapien skeleton, discovered in Somerset in 1903.
Their 3D-printed skulls sit to the right, on an enormous bookshelf that fills the wall. “Sometimes the skulls are on the shelf for years and we get to know them,” says Adrie. It was a thrill to have a “fresh new face”, a rare female Neanderthal at that.
Below them is a plaster model of a 1.7-million-year-old ‘half-ape half-man’, as Adrie puts it, and the head of a three-foot-tall ‘island dwarf’ from Indonesia, who might have encountered Homo sapiens when they first settled in the area, around 60,000 years ago. !Imagine how [the smaller man] would have interacted with that guy,” says Alfons, motioning towards the silicone head of a modern-looking man on the floor. ‘The real world, it’s completely crazy. It’s like The Lord of the Rings.’
The pair have toured Europe’s great museums in search of early human specimens, taking casts of all the skulls they could get their hands on. Without one, “you cannot predict how the shadow and light will fall on an extinct face”, Adrie says. In the days before the internet, Alfons scoured university libraries and bookshops for drawings of human and animal skulls. “One picture of an animal was like a trophy.”
Now Adrie and Alfons, 57, are the world’s most famed ‘paleoartists’, and it’s the museums that come to them with news of finds. At the back of their studio are two top-secret works in progress, modelled on skeletons about which nothing has yet been published in scientific journals. The twins will introduce their prehistoric faces to the world.
The brothers are identical, and behave more like one person split in half than two individuals, referring to themselves both as ‘I’ rather than ‘we’. They are loud, with matching tufts of messy dark hair, and can be told apart only by their glasses: Alfons wears black frames, Adrie silver. With a childlike playfulness they laugh heartily, making Neanderthal sounds or standing in hunting poses with imaginary bows and arrows.
The two work in tandem, one on a model’s head, the other on its body, switching with each new assignment. Their close relationship is ‘perfectly the same’ as it always has been, says Adrie, throughout their lifelong shared obsession with the prehistoric world.
“We were not good in school, the only thing we could do was drawing,” explains Alfons, and though the two had “an interest in biology and history, we are not good at maths”. They were transfixed by the early human species who walked the Earth, “especially Neanderthals”, and by the slow crawl of history, from ape to ape-man to man.
“I’ve got some very rare specimens,” Alfons says delightedly as he introduces two little cartoonish heads. One, a Neanderthal with furry eyebrows made when the twins were seven, has a “great big nose” but “no chin”.
“You cannot argue with this one,” Alfons jokes. The other, an ape-man sculpted when the pair were 12 and sitting in classrooms for ‘endless talks about human evolution’, has a furrowed brow and a serious glare.
Most fascinating of all to the Kennis twins as children was “the skull within a head”, human or animal. “We’d drive to school and always have a plastic bag somewhere, so if there’s roadkill on the road and it’s a bit intact, not too flat, then we’d shove it in our bags and take it home,” says Adrie. “It was just part of the job.”
“We’d boil it in water and extract the skulls,” says Alfons, completing the story. “Later they come in very handy if you draw prehistoric animals. If you know what house cats are like, you know a little bit of what makes a prehistoric cat.”
Today they have a set of more exotic catches on their shelves, including gorillas, kangaroos and mongeese. “We have a good connection from the zoo, so we get dead animals to dissect.”
Adrie and Alfons were illustrators before they were sculptors, using their skulls to craft models, which became references for lifelike drawings of sabre-toothed tigers and marsupial lions. Their first commission came in 1998, from a publisher in Amsterdam, for a children’s book about the evolution of birds. Then they were asked to draw people for another children’s book, and then for museums. On seeing the twins’ models, buyers soon decided that they’d rather pay for those instead.
Their human figures are not intended as completely faithful portrayals but rather as “interesting characters”, they say. As Adrie puts it, “We never say we make 100 per cent real reconstructions.” DNA sequencing may provide the colour of a character’s skin and hair, but it is the twins who imagine their gaze, their hairstyle, tattoos, scars and expressions.
The pair draw their inspiration from old ethnographic film and modern photography, which shows the behaviour of the hunter-gatherer tribes alive today, some of whom they’ve visited themselves. They have a favourite image: a woman from Papua New Guinea breastfeeding, with a large tobacco cigar in her mouth.
“Looking at anthropological documentaries and pictures about hunter-gathering cultures brings us closer to this prehistoric world,” Alfons says. “That’s what we like very much.” The two would like to use the image to make a reconstruction one day, but “we know that museums worry a lot about public perceptions, especially with issues about nakedness”. 
Though always controversial, the twins’ innovation has also brought them success. “We were more or less the first guys to make Neanderthals with friendly faces,” says Adrie. “Some people had the opinion that the expressions were much too human-like because we don’t know if the Neanderthals could laugh like this,” he continues. “But modern humans and Neanderthals interacted, so we imagine that they communicated in similar ways.”
Yet there is little to be gleaned from the modern life we know about what the Neanderthal world was like, the twins believe. “The Western world is such an alien, alien world, compared with the prehistoric world,” says Alfons. “In the Western world today people are sitting for most of the day behind desks and living in big cities. It’s crazy.” Adrie agrees that the modern world is ‘alien’.
In their work, the two are almost always on the same page, and that’s how they like it. “If I’m working on [a model] with my hands and I say, “Look,” and he doesn’t really respond, it’s wrong,” says Adrie. “As long as he thinks it’s OK, then I don’t mind what the whole world thinks about it.”
They have been under fire from the Left and Right alike. When the two presented their reconstructed Cheddar Man, the 10,000-year-old Brit, in 2018, some were outraged by his dark skin. An earlier reconstruction of Cheddar Man had been white, an assumption challenged by the DNA analysis used to inform the twins’ model.
Then when the twins finished their reconstruction of an 800,000-year-old Homo erectus woman for a European museum, with her chin resting in her hand and her fingers curled into her quizzical expression, curators “got complaints from people who probably framed the reconstruction as a dark-skinned modern woman, and wanted to know why we put her in such a sexual pose”. It isn’t a construction that the two recognise: they are depicting a time “before white and dark existed”.
Adrie finds both reactions frustrating. “They put their own filter they have in their minds on our reconstructions. We want to try to make the reality,” he says. Alfons agrees: it’s “terrible, terrible”. They would like to go further in their efforts to represent the past in a nuanced way, but it is a difficult balance. “How much work do you want?”
Why do museums, so frightened of the culture wars, keep coming back for the brothers’ sculptures? They falter. ‘Even with old chimp-like ancestors, the human expression makes contact with a visitor in one way or another,’ says Alfons eventually.
But it seems to the twins that curators and museum-goers alike are “becoming more conservative”. Alfons recalls being sent a letter by a father, who was angry that his daughter had seen their naked Cro-Magnon man at the Natural History Museum. “The whole world is more conservative than you’d expect.”
Adrie and Alfons themselves grew up in Veghel, in the south of the Netherlands, which Adrie says had a bit of a ‘small-town mentality’. “We wanted to go to art school, but it was, ‘No, you’ll get no job.’ So we went to school to be art teachers,” Alfons says.
Yet when the two graduated, work in schools was scarce. They picked up half-day shifts at a psychiatric hospital “and then we would paint the whole day and night, for fun”.
It would be wrong to think, because of their former day job, that the two have a fascination with people and their behaviour: “No, no, no, there’s no connection,” they both say, in near-perfect synchrony. “We are interested in the appearance of people, all people in the world, in characters, evolution and appearance,” Alfons says.
Alfons, who has two children, aged 14 and 18, with his girlfriend, spent lockdown painting model planes with them, and reading about the “transition from sailing ships to steam-engine ships”. Adrie also has a girlfriend, but has never had children. They have an older sister, who lives in Amsterdam, but their parents died when they were “very young”. These days what little free time they have is spent reading about prehistory, or gardening. The pair live separately and come together to work at their studio, which backs on to Adrie’s house.
Arnhem is not a large city, but here the two fit in. One of their friends from a nearby studio “does dinosaur designs”. Another is a taxidermist who works with “bats, chimpanzees, gorillas, even dead whales”.
The brothers had lived a half-hour drive away in Nijmegen, a big student city near the German border, and both moved to Arnhem with their girlfriends. “There I read a scientific paper for the first time,” Alfons recalls. “There was a library with [the journals] Nature and Science. Even before the internet I was on top of scientific news.”
These days the two use their encyclopaedic knowledge to present the unexpected. Adrie picks up a tiny to-scale model of their Homo sapiens Předmostí, who is shown painting tribal stripes on his body. “This guy is not so friendly in the face, but he’s making big stripes on his legs,” says Adrie. When it comes to a model of an ancient male, they like to add “something soft”. The character’s life-size counterpart stands in the Natural History Museum in London. This contrast is “why so many people like him”, Adrie believes.
Museum curators aren’t always so enthusiastic. “We saw this guy from Papua New Guinea with parts of his beard and hair shaved off. Amazing-looking, like a lion, and very impressive,” says Alfons. “So we wanted to put it on our model. But when people at the museum saw it, they really didn’t like it. They expected a dull ponytail, but we couldn’t change it. In the end the visitors loved it, and he became the icon of the museum.”
“We see few documentaries that we like,” Adrie adds, because they consider them out of date, with not much change in the past 20 or 30 years. “It’s old-fashioned. The first Europeans are now a little darker [in skin colour],” he continues, but all the male Neanderthals shown are “gnome-like” and have “a six pack right out of the gym”.
“Cultures with very different aesthetics and beliefs are cancelled, and everything is modelled too much on our current aesthetics,” Alfons says. In museums and documentaries “we don’t see any reflection of an anthropological hunter-gathering world, but an over-dramatised play, with little reality in it.”
By treating prehistoric humans in this way, rather than looking at how modern hunter-gatherers behave, “you’re saying there’s something wrong with other cultures”, says Adrie. “We feel a bit troubled because we enable the museums to sustain this image. We’d like to show this other world, this prehistoric world, with other aesthetics and beliefs.”
Today real human features are “gone from the internet because of algorithms”, Alfons says. “In the beginning we were more free because we’d make asymmetrical breasts for women,” Adrie adds. “Ten years later you could never do that, because everyone is so influenced by social media. Everyone expects to see the same idealised body proportions and shapes.”
But the internet has also made their work much more famous. The twins have had fanatics ask them to make reconstructions of aliens sighted on supposed UFOs, and even of Jesus, from the Turin shroud. ‘I said there was no evidence,’ says Alfons firmly. ‘If you find some bones then maybe I’ll think about it.”
After Shanidar Z starred in her Netflix documentary, ‘Kurdistani visitors came up to the Shanidar Cave in their hundreds,” says
Professor Graeme Barker of the University of Cambridge’s Department of Archaeology, who leads the excavations there.
“They’d got on their phones these photos of Shanidar Z’s reconstructed head, but through some app had turned her into a Kurdistani woman in her 40s, in a traditional dress.” Locals called her ‘the mother of Kurdistan’.
This is the sort of modern filter that the twins quite like. Shanidar Z “may have nothing to do with [modern Kurdistani people] genetically”, Alfons says, “but it’s OK to be proud of the thing”. Adrie agrees. “For us it’s OK, we don’t mind. It’s beautiful.”