Piltdown Man: The Fake Ancestor That Fooled Science for Four Decades

On the evening of 18 December 1912, the meeting room of the Geological Society of London was about as full as it had ever been. Alongside the Fellows, 74 guests had squeezed onto the benches or stood at the back. They had come to hear a Sussex solicitor and amateur antiquarian named Charles Dawson read a paper that opened like a country memoir: “Several years ago, I was walking along a farm road close [to] the Piltdown Common, Fletching (Sussex).”

By the end of the evening, Dawson and his co-author, Arthur Smith Woodward, Keeper of Geology at the British Museum (Natural History), had given the world a new human ancestor. They called it Eoanthropus dawsoni, “Dawson’s dawn-man.” The press called it Piltdown Man. For roughly four decades it sat in textbooks and on evolutionary charts as a candidate for the missing link between apes and humans.

It was a fake. The skull was human but far from ancient, the jaw belonged to an orangutan, and the teeth had been filed to look human. What makes Piltdown worth revisiting is not only that it fooled people. It is how long it took to unravel, why so many experts wanted to believe it, and how a team using CT scanners and ancient DNA finally tied nearly every piece to one man in 2016.

A letter, a gravel pit and a “coconut”

The story officially begins with a letter. In February 1912 Dawson wrote to Woodward that he had found a “thick portion of a human(?) skull which will rival H. heidelbergensis in solidity.” The comparison was pointed. The type specimen of Homo heidelbergensis had been discovered in Germany in 1907, and a find of its own would raise Britain’s standing in the story of human evolution.

Dawson’s account of how he came by the first fragment was colorful. He said workmen at a gravel pit near Piltdown had found a skull and broken it up, believing it to be a fossilized coconut, and that one of them handed him a piece. Through the summer of 1912 Dawson and Woodward dug at the pit and sifted its spoil heaps. Dawson alone turned up more skull fragments and half of a lower jaw.

What they presented in December was an odd combination. There were pieces of a thick, human-looking braincase and an ape-like jaw holding two worn molars. Around them lay primitive stone tools and scraps of fossil animals, all stained the same dark reddish-brown as the gravel. The animal fossils suggested great age, and Woodward argued the creature had lived at least 500,000 years ago.

Woodward’s reconstruction gave the skull a brain about two-thirds the size of a modern human’s, set above a jaw he judged to be almost indistinguishable from a young chimpanzee’s, apart from the human-like wear on the molars. The combination fit a popular idea in English science at the time: that our ancestors grew big brains first and human faces later.

The timing helped. Arthur Conan Doyle’s The Lost World had just finished its run in The Strand magazine, and the public was primed for stories about deep time and lost creatures. Piltdown Man was, as a Geological Society history of the night puts it, “the oldest known Englishman.”

An argument that produced a tooth

Not everyone liked Woodward’s version. At the Royal College of Surgeons, the anatomist Arthur Keith used casts of the same fragments to build a very different skull, larger-brained and more modern-looking, which he named Homo piltdownensis. The two men argued in particular about the missing canine tooth. Woodward’s model gave the creature a big, ape-like canine.

On 11 August 1913, at the International Medical Congress, Keith ridiculed Woodward’s reconstruction, and The Times reported it the next day. Eighteen days later, on 30 August, a canine turned up in the Piltdown spoil heaps. It was found by Pierre Teilhard de Chardin, a young French Jesuit and geologist who had joined the digs, and it looked remarkably like the model tooth Woodward had already put in his reconstruction. Its timely appearance quieted many critics.

The finds kept coming through 1913 and 1914. The last big one at the first site was its strangest object: a slab of what was probably fossil elephant bone, carved into a shape so suggestive that it was immediately nicknamed the “cricket bat.” Then in 1915 Dawson wrote to Woodward on postcards to say he had found more remains at a second site, which came to be called Piltdown II. It lay about 3 kilometers from the first. There he reported a piece of frontal bone, a fragment from the back of a skull and a molar tooth.

Dawson never told anyone exactly where Piltdown II was, and Woodward could not get the location out of him. Dawson’s health was failing, and he died in August 1916. Woodward did not present the second set of finds until months after Dawson’s death. Nothing significant was ever found at either site again.

The doubters who were right too early

It would be wrong to say science swallowed Piltdown whole. In 1913 David Waterston of King’s College London argued in Nature that the remains were simply an ape jaw and a human skull that had ended up together. The French paleontologist Marcellin Boule reached the same view in 1915, and the American zoologist Gerrit Smith Miller Jr. argued that the jaw came from a fossil ape. In 1915 Miller also wrote a sentence that reads like prophecy:

Deliberate malice could hardly have been more successful than the hazards of deposition in so breaking the fossils as to give free scope to individual judgment in fitting the parts together.

In 1923 the anatomist Franz Weidenreich came closest of all. After examining the remains, he concluded they were a modern human cranium and an orangutan jaw with filed-down teeth.

Yet Piltdown II blunted the skeptics. An ape jaw and a human skull might wash into the same gravel by chance once, but matching remains at a second site made coincidence much harder to argue. In 1921 Henry Fairfield Osborn, president of the American Museum of Natural History, looked at both sets of finds and declared that the jaw and skull belonged together “without question.” The new fragments, he said, “were exactly those which we should have selected to confirm the comparison with the original type.” Even Keith accepted the second site, though he kept private doubts.

Part of the trick’s staying power was access. The original bones were generally kept locked away and shown to a select few, so most researchers studied plaster casts. A cast shows the shape of a bone well enough. It does not show the scratches left by a metal file.

The site itself was honored in stone. On 23 July 1938, at Barkham Manor in Piltdown, Keith unveiled a memorial marking the spot where, as the inscription says, Charles Dawson “found the fossil skull of Piltdown Man.” Keith told the crowd that “the name of Charles Dawson is certain of remembrance.” He was right, though not in the way he meant.

The fossils that did not fit

While Piltdown sat in its museum case, the rest of the human fossil record kept growing, in China, Indonesia and Africa. None of the new finds had Piltdown’s peculiar recipe of an ape’s jaw under a human’s braincase. Many showed the reverse: small brains above jaws and teeth that were already fairly human.

The most important of them was a child’s skull that quarry workers at the Buxton Limeworks in Taung, South Africa, turned up in 1924. The anatomist Raymond Dart announced it in 1925 as Australopithecus africanus. Dart argued it was a transitional form between apes and humans. The British establishment, with Keith prominent among it, dismissed it. Keith described the fossil as a juvenile ape that had nothing to do with human ancestry.

The turnaround came in 1947. Wilfrid Le Gros Clark, an Oxford anatomist who had traveled to Johannesburg to study Dart’s skull and new adult fossils found by Robert Broom, told the First Pan-African Congress on Prehistory that the australopithecines were early members of the human family. Keith publicly agreed in Nature that year: “the evidence submitted by Dr. Robert Broom and Professor Dart was right and I was wrong.” By the late 1940s many specialists already treated Piltdown as an awkward anomaly. What nobody had yet done was prove it was a forgery.

A chemical clock in the bones

The first hard evidence came from chemistry. Bones buried in the ground slowly absorb fluorine from groundwater, so a bone that has lain in a gravel bed for hundreds of thousands of years should carry much more fluorine than one buried recently. The method cannot give a precise date, because soils differ, but it can show whether bones from the same deposit were really buried for the same length of time.

In 1949 Kenneth Oakley, a geologist at the Natural History Museum, ran fluorine tests on the Piltdown remains. They suggested the material was at most about 50,000 years old, not nearly old enough to be a missing link. That alone made Piltdown an even stranger fossil. Further work showed that the jaw and teeth held far less fluorine than the skull pieces.

Oakley teamed up with two Oxford scientists who shared his suspicions: the human biologist Joseph Weiner and Le Gros Clark, the same anatomist who had rehabilitated the Taung Child. In November 1953 the three published “The Solution of the Piltdown Problem” in the museum’s geology bulletin and presented their findings at the Geological Society, in the very room where Piltdown Man had been introduced 41 years earlier.

Their conclusion was blunt. The jaw and the canine were a recent ape’s, deliberately altered. The skull fragments were from a human who was not ancient at all. Someone had stained the bones to look old, using a solution of iron and chromic acid, and microscopic examination showed file marks on the teeth, which had been ground down to mimic human chewing. In a further report in 1955 the team showed that most of the rest of the material, including stone tools, had also been stained to match the local gravel. The animal fossils were real, but they had been gathered from many other places and planted in the pit. The “cricket bat” had been whittled with a steel knife.

Keith, who had built a career partly around Piltdown, lived just long enough to see it fall. He conceded the specimen was a forgery shortly before his death in January 1955. Woodward had died in 1944, before the exposure. His book on the subject, The Earliest Englishman, appeared after his death, in 1948.

Whodunit

Exposing the forgery did not settle who made it, and for decades the question became a parlor game. Over the years at least 20 people have been accused. Some suspected Teilhard de Chardin, the canine’s discoverer; the paleontologist Stephen Jay Gould argued that he conspired with Dawson. Others pointed to Martin Hinton, a volunteer in Woodward’s department who was skeptical of Piltdown. A trunk he left in storage at the museum was found in 1970 to hold bones and teeth carved and stained much like the Piltdown pieces.

There was even a case against Arthur Conan Doyle, who was known to play golf at the Piltdown site. The American historian of science Richard Milner suggested that the creator of Sherlock Holmes might have wanted revenge on a scientific establishment that had debunked one of his favorite psychics. Doyle’s devotion to Spiritualism was real enough, as his long clash with Harry Houdini over spirit mediums shows, but the Piltdown evidence against him was always thin.

Dawson himself, meanwhile, looked worse with every look at his record. The archaeologist Miles Russell of Bournemouth University went through Dawson’s antiquarian career and concluded that at least 38 of his discoveries were fakes. They included the teeth of a supposed early mammal, Plagiaulax dawsoni, “found” in 1891 and filed down much as the Piltdown teeth would be two decades later. Others were the Bexhill boat, a supposed hybrid vessel; the Pevensey bricks, billed as the latest datable finds from Roman Britain; a “Roman” statuette made of iron; and the Brighton “Toad in the Hole,” a toad supposedly sealed inside a flint nodule. “Dawson had the means, motive and opportunity,” Russell said, adding that “he also had form.”

The motive, as best anyone can reconstruct it, was recognition. Between 1883 and 1909 Dawson wrote or co-wrote more than 50 publications, none of which made his name. In 1909 he complained to Woodward that he had “been waiting for the big ‘find’ which never seems to come along.” Late that year his younger brother, a naval officer and defense-industry executive, was knighted. Six weeks later, Dawson’s wife wrote to the Home Secretary asking that her husband be recommended for an honor for his unpaid services to the national collections. Nothing came of it. Piltdown did bring a nomination to the Royal Society in 1913, but he was not elected, and he died before he could try again.

CT scans, putty and one orangutan

In 2016, a century after Dawson’s death, a team led by De Groote of Liverpool John Moores University and Chris Stringer of the Natural History Museum published the results of an eight-year reexamination in Royal Society Open Science. They put every Piltdown I and Piltdown II specimen through high-resolution CT scanning, chemical analysis, precise measurement and ancient DNA testing.

The ape parts came from a single animal. Analysis of the shape of the molars’ inner enamel boundary classed all three molars, including the one from Piltdown II, as orangutan. Measurements tied the canine to the jaw. The team also recovered short stretches of mitochondrial DNA from the canine and the Piltdown II molar, and the two carried the same genetic signature. That linked the “second site” back to the jaw from the first. The DNA pointed to a Bornean orangutan, most likely from populations now living in southwest Sarawak.

The human parts came from at least two individuals, possibly three, and possibly medieval. Older radiocarbon dates on the bones disagree with each other, and the team’s own attempts to redate them failed because of contamination, so the exact age remains uncertain.

The most telling evidence was a consistent way of working. Throughout the collection, the scans found small gravel particles packed into hollow spaces in the teeth and bones, with the holes plugged by little pebbles that matched sediment from Piltdown. The plugs were held in place by the same putty, rich in zinc and zirconium, which looked like a white dental filling material. The same putty had been used to rebuild one of the molars and to seat the teeth back in the jaw.

The scans also showed how roughly the jaw had been treated. The forger appears to have cracked the jaw while trying to break it apart and gouged out bone below the molars, which only makes sense if the teeth had been pulled from their sockets. Once out, the teeth could be ground flat on an abrasive surface to fake human wear, then glued back with putty. The third molar socket was left empty, perhaps because the mix set too fast to seat it properly. The authors concluded that the forger “was not a trained conservator”: bones fractured, putty set too quickly and teeth cracked while being filed.

Because the same methods appear on material from both sites, and because Dawson was the only person connected with Piltdown II, the team concluded that a single forger was responsible, and that this was most likely Dawson. “That has to be Dawson, there’s no doubt about that,” Stringer told BBC News. He allowed that someone else could have supplied the specimens, but Dawson was the central figure. The analysis also cleared several others. De Groote said of Conan Doyle: “Obviously he could write a good story, but he probably would never have had the skill or the scientific knowledge to prepare a forgery like this one.”

Why it worked, and what it still teaches

Piltdown was not a brilliant forgery. It was a crude one aimed precisely at what its audience wanted. British scientists expected the earliest humans to have big brains and ape-like jaws, and many wanted a British fossil to rival finds on the Continent. Gould argued that national pride and cultural prejudice helped Piltdown win acceptance. Dawson, the 2016 team wrote, was “a great networker” who knew what the scientific community was hoping for, and he seems to have listened. When critics asked about the canine, a canine appeared.

The episode belongs alongside other cases where wanting something to be true did most of the work, from the newspaper readers who believed in man-bats on the Moon in 1835 to the European courts dazzled by a chess-playing “automaton” with a man hidden inside. It also echoes the rivalries of the Bone Wars, when reputations rode on who could announce the next great fossil first.

It is also a story about secrecy. The forgery might have been caught much earlier if more people had been allowed to handle the originals instead of casts. De Groote argued that paleoanthropology “is still very much a field of fossil hoarding,” and pointed to Homo naledi, whose skeletons were quickly made available as printable 3D files, as a better model.

And in the end it is a story about science correcting itself, slowly. The doubters of 1913 were right, the chemistry of 1949 and 1953 proved it, and the scanners of 2016 found the forger’s fingerprints in the putty. De Groote’s advice applies far beyond fossils: “If something fits a hypothesis maybe too well, question it again.”

Further reading