Tiny fossil reveals new truth about Neanderthal expansion
Out of the museum, and into history books.
After spending decades tucked away in a private collection, a tiny, ancient relic has just transformed what scientists know about the southward expansion of Homo sapiens' best-known relative: Neanderthals.
Discovered close to 100 years ago, a tooth which likely belonged to a nine-year-old Neanderthal child has now been fully analyzed. Instead of upholding established beliefs about both Homo sapien tool use and Neanderthals' migration, the study's findings shatter a connection between these ancient peoples and their tools.
The findings were published Monday in the journal Scientific Reports.
Why it matters — After decades of telling ourselves the same stories about ancient humans, these theories begin to feel like an indisputable fact. But this study shows how previously disregarded artifacts may in truth be waiting for new technology to reveal their secrets — and ultimately, rewrite our origin story.
Here's the background — At this point, it is well-documented in genetics studies that Neanderthals and Homo sapiens were not picky when it came to crossing species lines to find mates. Paleoarchaeologists are particularly interested in how this may have happened in the ancient Levant region, which today encompasses much of the Middle East.
"We can't make a simple link between this technology and Homo sapiens."
A wealth of archaeological findings from the 1900s suggest Neanderthals and Homo sapiens would've occupied this region at different times, but the authors behind this new paper argue crucial evidence has been ignored which proves otherwise — including a loose, Neanderthal tooth originally discovered by Dorothy Garrod (a pioneering archaeologist in her own right) in the spring of 1928.
Dorothy Garrod, c.1913. Photograph by Newnham College, Cambridge.
Garrod excavated Shukbah Cave, a site located on what is now Palestine's West Bank. There, she discovered a strange and mostly intact molar, nestled among a smattering of tools. These tools included stone cores and points characteristic of Nubian Levallois technology — used by Homo sapiens. But the tooth told a more complex story.
Shukbah Cave, originally excavated by Dorothy Garrod in 1928.
Clément Zanolli, from Université de Bordeaux, is a co-author of the new study. In a statement, Zanolli says that Garrod knew there was something special about this dental specimen. But before she could examine it further, the entire collection was swept behind the lock-and-key of a private collector.
"Professor Garrod immediately saw how distinctive this tooth was," Zanolli says.
It is only now that the collection has passed to London's Natural History Museum that modern archaeologists can pick up where Garrod left off.
"We've examined the size, shape and both the external and internal 3D structure of the tooth, and compared that to Holocene and Pleistocene Homo sapiens and Neanderthal specimens," Zanolli says.
"This has enabled us to clearly characterize the tooth as belonging to an approximately 9-year-old Neanderthal child."
Jimbob Blinkhorn is the study's first author and a researcher at the Max Planck Institute for the Science of Human History. He explains in an accompanying press statement why studying the tooth alongside the tools from the cave is crucial to understand the full spectrum of hominin behavior in the region.
"Sites where hominin fossils are directly associated with stone tool assemblages remain a rarity," Blinkhorn says.
"[B]ut the study of both fossils and tools is critical for understanding hominin occupations of Shukbah Cave and the larger region."
To better understand this crucial part of ancient history, the researchers turned to modern 3D analysis.
What they did — The researchers use 3D modeling to create a computer model of the tooth which they could then manipulate without causing damage to the artifact itself.
With the help of X-ray analysis, the researchers were able to generate a model which captured both external and internal characteristics of the tooth — from the pointed dental crown, down to its roots.
A 3D reconstruction of a 9-year-old Neanderthal's tooth.
Using this 3D model, the researchers compared the tooth to other specimens known to belong to ancient Neanderthal and Homo sapiens and determined that it likely belonged to a young Neanderthal, between 7- and 12-years-old.
What they discovered — Confirming this tooth belonged to a Neanderthal, instead of a Homo sapien, represents a paradigm shift, the authors suggest. It was found amongst tools previously assumed to be Homo sapiens — but this new discovery suggests the tools belonged — at least in part — to Neanderthals.
"This is the first time they've been found in direct association with Neanderthal fossils, which suggests we can't make a simple link between this technology and Homo sapiens," Blinkhorn says.
Tools uncovered at Shukbah Cave.
Ultimately, the discovery suggests Nubian technology can not be used as a definite marker of Homo sapien societies, because Neanderthals may have also used such tools.
What's next — The discovery of this Neanderthal tooth also marks the most southern Neanderthal fossil discovered yet. Together, the discovery shows Neanderthal society was not only more complex, but also more wide-spread than we previously assumed.
Chris Stringer of the Natural History Museum, the institution where the fossil was kept, said in a statement the finding may fundamentally alter how archaeologists chart Neanderthals' territory — and even how they may have migrated into Africa.
"Up to now we have no direct evidence of a Neanderthal presence in Africa," Stringer says.
"But the southerly location of Shukbah, only about 400 kilometers from Cairo, should remind us that they may have even dispersed into Africa at times."
Abstract: Neanderthals occurred widely across north Eurasian landscapes, but between ~ 70 and 50 thousand years ago (ka) they expanded southwards into the Levant, which had previously been inhabited by Homo sapiens. Palaeoanthropological research in the first half of the twentieth century demonstrated alternate occupations of the Levant by Neanderthal and Homo sapiens populations, yet key early findings have largely been overlooked in later studies. Here, we present the results of new examinations of both the fossil and archaeological collections from Shukbah Cave, located in the Palestinian West Bank, presenting new quantitative analyses of a hominin lower first molar and associated stone tool assemblage. The hominin tooth shows clear Neanderthal affinities, making it the southernmost known fossil specimen of this population/species. The associated Middle Palaeolithic stone tool assemblage is dominated by Levallois reduction methods, including the presence of Nubian Levallois points and cores. This is the first direct association between Neanderthals and Nubian Levallois technology, demonstrating that this stone tool technology should not be considered an exclusive marker of Homo sapiens.
