In caves and rock shelters around the Levant, archaeologists keep finding gazelle scapulae (shoulder blades) marked with a series of regular notches. Scientists still aren't sure what kind of information the enigmatic marks once conveyed or how the bones themselves might have been used or displayed, but they may be able to tell us something about how early human cultures spread through Eurasia.

Put another notch in your... gazelle scapula?

Hayonim Cave in Western Galilee, Israel, overlooks the right bank of a large wadi a few miles from the Mediterranean shore. There, archaeologists found eight gazelle scapulae, mostly broken, along with hearths, tooth pendants, stone chips, and signs of ochre use within layers of sediment dating to the Upper Paleolithic. The bones are marked with rows of 0.5-2.5mm wide, 4-5mm long notches regularly spaced 0.5 to 7mm apart. They were put there by a stone blade; on the only unbroken scapula in the set, there are 32 notches, but some have as few as three.

The notches aren’t on the same parts of the bone where you'd expect to find cut marks from butchering an animal. Butchering cuts also tend to be shallower and shorter, and the surface of a hacking or cutting mark looks very different under a microscope than a notch made by sawing into a pre-scraped surface.

The notches always mark the thickest parts of the bone, on the posterior side—the side that faces the rear of the animal. Microscopic analysis shows that whoever made the notches also took the time to scrape the surface of the bone smooth beforehand. That's a lot of work, and most bone tools from the same time period aren't nearly so carefully prepared; bone awls and chisels were usually worked just enough to sharpen the business end. These markings clearly weren't the product of idle fiddling.

Their meaning must have been intuitively obvious to the people who lived in the Levant 34,000 to 38,000 years ago. After all, it mattered enough that people put some effort into expressing it.

José-Miguel Tejero of the Centre National de la Recherche Scientifique de France is the lead author of a new paper describing the findings. Tejero and his colleagues say the best explanation is that the marks are probably some form of symbolism. There’s plenty of evidence that people had been using visual symbols, from jewelry to cave paintings to decorative designs, for some time before the first settlers ventured beyond Africa. Being able to convey ideas like "There's water here," "I am an important person in this group," or "We killed a large mammoth" with visual cues had an adaptive advantage as people lived in ever-larger groups and interacted with other groups more often.

Tejero et al. 2018

Tejero et al. 2018

Tejero et al. 2018

Tejero et al. 2018

Tejero et al. 2018

Tejero et al. 2018

Unique cultural signature

At European sites in Italy, Belgium, France, and central Europe, notched marks like these have been found on antlers, tusks and teeth, ribs, limbs, and other bones from reindeer, red deer, mammoth, and several bovid species. But in the Levant, it's all about the gazelle scapulae, except for a single notched hyoid bone found in Manot Cave—and even that was from a gazelle.

“We can assume that notched bones in Europe, in the African Middle Stone Age, as well as in the Levantine Aurignacian shared a similar purpose—that is, to convey individual or group information. Nevertheless, what makes the sample of the Levant in general and Hayonim in particular unique is the homogeneity of the raw material, taxa, and anatomical part selected,” said Tejero. (That's academic for "It's always gazelle scapulae with these guys.")

The numbers are also unusual. Tejero and his colleagues found eight marked scapulae at Hayonim Cave and four more at Manot Cave—in Europe, notched bone artifacts usually show up in smaller numbers, one or two to a site. Archaeologists aren’t sure yet why that is, but the sheer homogeneity of these artifacts, and the fact that they're so common, may make them a good diagnostic marker of a culture called the Levantine Aurignacian, which seems to have flourished in a relatively small area along the eastern shore of the Mediterranean from about 34,000 to 38,000 years ago.

Aurignacian sites in the Levant share some other commonalities, especially in the types of stone tools and the techniques used to make them. But archaeologists are still debating about how Aurignacian culture got started and how it spread. The Aurignacian culture existed in Europe, too, from 43,000 to 26,000 years ago, but it was much more widespread, with more variation between places. There are enough similarities with the Levantine Aurignacian to make it likely that the two cultures are related.

Tejero and his colleagues say that if these scapulae are unique to the Levantine Aurignacian, then looking at where they're found and whether they change over time could help archaeologists understand how this culture spread into Europe and how it changed when it got there.

What does it all mean?

“One aspect of symbolic material culture, and possibly the most significant benefit of symbolical behavior in general, is its ability to link the individual or group with other individuals and groups through the inter- and intragroup transmission of information,” Tejero told Ars. “Such signals thus may include identification (class affinity, social group affiliation, rank, and so forth), authorship, and ownership.”

Tejero and his colleagues say the marked scapulae may have been worn as pendants, with a string tied around the narrow neck of the scapula, the part that attaches to the humerus. The Himba people of Namibia wear pendants of a similar size to indicate marital status, and we've found evidence of jewelry at other sites from this period, so it’s plausible—but at this point, it’s still just speculation. The fact is that we're just not sure what the notches in the scapulae would have conveyed to people in the know.

"The use of artifacts to transmit messages is advantageous when used to communicate information to people who are in 'the middle distance'—that is, those people who are not so close to the sender that the messages are already known and not so distant that the meaning of the message cannot be deciphered," Tejero told Ars. Thirty-four thousand years later, we're well beyond the middle distance.

“Some authors suggested that this type of mark could be linked with a notation system marking lunar phases,” said Tejero. “However, the notches discussed here were most probably made in one session, on fresh bone, and likely by the same lithic tool.” That means the marks couldn’t have been made over a period of several months to mark lunar phases, and it rules out other kinds of tallies, too, like a count of days or successful hunts.

It's unlikely that we'll ever crack the code, but using these marked bones as tracers might help archaeologists track the spread of the culture that briefly flourished here, which can tell us something interesting about how early human culture spread—even if we don't get it.

PNAS, 2018. DOI: 10.1073.pnas.1717145115 (About DOIs).