In 1990, Cambridge palaeontologist Kenneth McNamara stumbled on a poignant illustration in an obscure book by a Victorian archaeologist. The find rekindled a childhood obsession, and after two decades of dogged research he discovered it's an obsession...
“I'm fascinated by the fact that people have been interested in this one obscure object, and that you can track it for this phenomenal amount of time.”
Dr Kenneth McNamara
The frontispiece of Worthington George Smith's 1894 book The Primaeval Savage is as striking today as it must have appeared over 100 years ago. Lying on her back, knees bent to form a lap, the skeleton's head and torso are turned down and to the left towards the skeletal remains of the infant she seems to be cradling.
Smith – an ecclesiastical draughtsman turned botanical illustrator and amateur archaeologist – produced the image after unearthing the remains from a flattened Bronze Age burial mound on the chalky soil of Dunstable Downs in 1887.
But the extraordinary thing about Maud – the name he gave the woman he found – is not when or where she was buried, but what was buried with her. Because around the skeletons Smith discovered not one or two but more than 200 fossil sea urchins.
Dr McNamara describes fossil urchins as “balls of flint engraved with a five-pointed star”. Found like other flints in layers of chalk, the fossils are all that remain of two extinct species of sea urchin known as Micraster and Echinocorys that burrowed in the mud on the sea bed some 70 million years ago.
“In life they had a calcium carbonate shell and inside there wasn't much except guts and gonads,” he explains.“When they die the inner parts rot and there's this complicated process of flint forming in chalk.”
“At particular times you get a band of flint formed by silica from the great forest of sponges that lived on the sea floor. Given the right conditions it forms a silica gel which slowly dissolves, working its way down into the sediment, and the shell of one these urchins is a perfect space – an internal mould – for the silica to fill.”
Like many fossil hunters, sea urchins were prize trophies for the young McNamara on weekend forays to the beaches and South Downs near his Brighton childhood home. “I scoured the downland quarries for urchins. I can't say that I was ever very successful,” he admits. “But the feeling was always there that the next rock I hit with my hammer just might contain my Holy Grail.”
Neglected history
As the adult Dr McNamara began digging into the neglected history of the star-crossed stone, he unearthed an intimate human association with these obscure objects – and echoes of his own collecting – receding back in time for almost half a billion years.
“I've been working on fossil urchins since the late 1970s because they are a great tool to use in evolutionary studies – that's my main interest – and they were one of the first fossil groups used after Darwin's Origin of Species to back up some of his ideas,” he says. “But I'm a palaeontologist, so this archaeological aspect was just a little hobby.”
His little hobby, however, revealed that although Maud was buried with the largest number of fossil sea urchins ever found in a single grave, she was not unique. Humans and urchins have been interred together across thousands of miles and for thousands of years.
As well as in burials, fossil sea urchins have been found forming the centrepiece of carefully fashioned flint tools. And, most astonishing of all, this behaviour extended beyond our own species, Homo sapiens, to our ancestor H. heidlebergensis and our fellow hominid, Neanderthal man.
“You find fossil sea urchins in tools or burials in the UK, France, Belgium, Germany, Jordan, Egypt, Sudan and Niger,” explains Dr McNamara. “The oldest is in the Swanscombe hand axe, around 400,000 years old, and there others from the early Palaeolithic in France, so it's not an isolated example.”
“Fossil sea urchins began to appear in burials in the Neolithic. They have been found in burials from the Bronze and Iron ages, are common in Anglo-Saxon graves and the most recent was found in a 12th century grave in a Jewish cemetery in London where a young boy was buried with them,” he says.
And Dr McNamara discovered even more recent vestiges of this shared history. At St. Peter's in the Hampshire village of Linkenholt, he found that during the church's rebuilding in the 1860s, key parts of the mediaeval structure were preserved, including dozens of fossil sea urchins used to decorate two of its windows.
“I'm fascinated by the fact that people have been interested in this one obscure object, and that you can track it for this phenomenal amount of time,” he says. “For 400,000 years, people have wanted to pick them up, which is an urge I've always had, and three species of hominid have done the same thing. It's absolutely astounding.”
Deep-seated trait
So how does he explain this enduring fascination with a simple ball of flint marked with a five-pointed star?
At one level, Dr McNamara believes it points to an ancient and deep-seated human trait. “So many people have this collecting urge,” he says. “And if you ask collectors, it's more about the excitement of the hunt. I think for most people it's not the possessing, it's the finding of it.”
Which explains part, but not all, of the story. Like our ancestors we have an urge to collect, but why did they collect this one object with such a passion? The answer, Dr McNamara argues, lies in the five-pointed symmetry of the star-crossed stone.
According to other academics who work on the evolution of cognitive development, the appearance of bilaterally-constructed tools is evidence of the mind beginning to think in abstract ways, and to appreciate the aesthetic. If that's the case, it's not hard to see the attraction of the five-pointed star.
Neither is it difficult to imagine these objects gradually assuming a spiritual significance, as representations in miniature of the human form, or the status of a lucky charm with powers to ward off evil.
Now that Dr McNamara's book – 20 years in the making – has been published he admits to being slightly bereft. “It was hard work, but I loved writing it, and finishing it was traumatic. What do I do next?” he asks.
Perhaps a walk down King's Parade will ease the loss, because there, as in so many city streets, echoes of the star-crossed stone are everywhere, carved into buildings, worked into flags and in consumer goods brands from beer to coffee. Maud, it seems, will never be far from Dr McNamara.
Dr Kenneth McNamara is a senior lecturer in the Department of Earth Sciences and a fellow of Downing College. His book The Star-Crossed Stone is published by the University of Chicago Press.