Scientists Trace an Ore Source for the Benin Bronzes

The Benin Bronzes — some roughly 3,000 stunning bronze artworks sculpted by African metalsmiths between the 16th and 19th centuries — were crafted from metal mined from Germany’s Rhineland region, a new study finds.

Researchers had long suspected that the masterfully crafted sculptures — created by the Edo people of the Kingdom of Benin, now part of modern-day Nigeria — were made from melted-down brass rings used as a currency during the trans-Atlantic slave trade, but confirmation proved elusive.

Now, scientists have used these metal rings, called manillas, recovered from five centuries-old Atlantic shipwrecks to trace the artworks’ provenance, confirming that their metal came from repurposed bracelets that had been originally used to purchase enslaved people.

By tracing the manillas’ metal, the researchers found the majority had been mined from western Germany. They published their findings on April 5 in the journal PLOS One.

“The Benin Bronzes are the most famous ancient works of art in all West Africa,” study first author Tobias Skowronek, a researcher of engineering and materials science at Technical University Georg Agricola in Germany, said in a statement.

“Finally, we can prove the totally unexpected: the brass used for the Benin masterpieces, long thought to come from Britain or Flanders [Belgium], was mined in western Germany.

The Rhineland manillas were then shipped more than 6,300 kilometers [3,900 miles] to Benin. This is the first time a scientific link has been made.”

Manillas, which get their name from the Spanish word for handcuffs or hand rings, served as a currency for European enslavers — namely the British, Portuguese, Spanish, Danish, Dutch and French — who sailed to Africa to trade millions of these rings for gold, ivory and slaves.

The manillas — highly valued in Africa, with different types traded among different peoples — were later made into the sculptures. Then, in 1897, British forces invaded Benin as part of a punitive military expedition, turning Benin’s royal court to rubble.

The British seized the Benin Bronzes before selling them to museums across Europe and the U.S.

To trace the rings’ murky origins, the researchers conducted chemical analyses on 67 manillas found across five Atlantic wrecks stretching from the English Channel to Cape Cod, Massachusetts, and in land-based dig sites in Ghana, Sierra Leone and Sweden. 

By comparing the elements found inside the manillas, along with their ratios of lead isotopes (variants of lead with different numbers of neutrons in their nuclei), to those inside the Benin Bronzes, the scientists found that both were similar to ores located in Germany’s Rhineland region.

The scientists noted that their findings match closely with the evidence from historical sources. For instance, a 1548 contract between a German merchant family and the Portuguese king details the specific requirements for the production of two types of manillas — each for a different region in Africa where one specific manilla type was more highly valued — carefully stipulating their weight, quality levels and shapes.

The discovery adds an extra dimension to Germany’s involvement with the Benin Bronzes, and to the broader story of the country’s part in Europe’s colonization of Africa.

Prior to this finding, historians focused mostly on Germany’s forestalled colonization efforts following the 1884-1885 Berlin Conference, where European powers met to agree on the carving up of Africa into distinct spheres of influence.

Nigeria and the Edo State Government have long been petitioning for the return of the artworks, the largest collection of which is in the British Museum in London.

The Horniman Museum, another U.K. museum, as well as Cambridge University, have given back their collection of Benin Bronzes, along with museums in Germany and the U.S.

What did Homo sapiens eat 170,000 years ago? Roasted, supersized land snails

Slow-motion large land snails made for easy catching and good eating as early as 170,000 years ago. Until now, the oldest evidence of Homo sapiens eating land snails dated to roughly 49,000 years ago in Africa and 36,000 years ago in Europe. But tens of thousands of years earlier, people at a southern African rock-shelter roasted these slimy, chewy — and nutritious — creepers that can grow as big as an adult’s hand, researchers report in the April 15 Quaternary Science Reviews.

Analyses of shell fragments excavated at South Africa’s Border Cave indicate that hunter-gatherers who periodically occupied the site heated large African land snails on embers and then presumably ate them, say chemist Marine Wojcieszak and colleagues. Wojcieszak, of the Royal Institute for Cultural Heritage in Brussels, studies chemical properties of archaeological sites and artifacts.

The supersized delicacy became especially popular between about 160,000 and 70,000 years ago, the researchers say. Numbers of unearthed snail shell pieces were substantially larger in sediment layers dating to that time period.

New discoveries at Border Cave challenge an influential idea that human groups did not make land snails and other small game a big part of their diet until the last Ice Age waned around 15,000 to 10,000 years ago, Wojcieszak says.

Long before that, hunter-gatherer groups in southern Africa roamed the countryside collecting large land snails to bring back to Border Cave for themselves and to share with others, the team contends. Some of the group members who stayed behind on snail-gathering forays may have had limited mobility due to age or injury, the researchers suspect.

“The easy-to-eat, fatty protein of snails would have been an important food for the elderly and small children, who are less able to chew hard foods,” Wojcieszak says. “Food sharing [at Border Cave] shows that cooperative social behavior was in place from the dawn of our species.”

Border Cave’s ancient snail scarfers also push back the human consumption of mollusks by several thousand years, says archaeologist Antonieta Jerardino of the University of South Africa in Pretoria. Previous excavations at a cave on South Africa’s southern tip found evidence of humans eating mussels, limpets and other marine mollusks as early as around 164,000 years ago (SN: 7/29/11).

Given the nutritional value of large land snails, an earlier argument that it was eating fish and shellfish that energized human brain evolution may have been overstated, says Jerardino, who did not participate in the new study.

It’s not surprising that ancient H. sapiens recognized the nutritional value of land snails and occasionally cooked and ate them by 170,000 years ago, says Teresa Steele, an archaeologist at the University of California, Davis who was not part of the work. But intensive consumption of these snails starting around 160,000 years ago is unexpected and raises questions about whether climate and habitat changes may have reduced the availability of other foods,  Steele says.

Researchers have already found evidence that ancient people at Border Cave cooked starchy plant stems, ate an array of fruits and hunted small and large animals. The oldest known grass bedding, from around 200,000 years ago, has also been unearthed at Border Cave (SN: 8/13/20).

Several excavations have been conducted at the site since 1934. Three archaeologists on the new study — Lucinda Backwell and Lyn Wadley of Wits University in Johannesburg and Francesco d’Errico of the University of Bordeaux in France — directed the latest Border Cave dig, which ran from 2015 through 2019.

Discoveries by that team inspired the new investigation. Excavations uncovered shell fragments of large land snails, many discolored from possible burning, in all but the oldest sediment layers containing remnants of campfires and other H. sapiens activity. The oldest layers date to at least 227,000 years ago.

Chemical and microscopic characteristics of 27 snail shell fragments from various sediment layers were compared with shell fragments of modern large African snails that were heated in a metal furnace. Experimental temperatures ranged from 200° to 550° Celsius. Heating times lasted from five minutes to 36 hours.

All but a few ancient shell pieces displayed signs of extended heat exposure consistent with having once been attached to snails that were cooked on hot embers. Heating clues on shell surfaces included microscopic cracks and a dull finish.

Only lower parts of large land snail shells would have rested against embers during cooking, possibly explaining the mix of burned and unburned shell fragments unearthed at Border Cave, the researchers say.