Tel Aviv University team deduces that baseball-sized rounded rocks found in caves just east of the modern metropolis were used hundreds of thousands of years ago for breaking open bones to extract marrow for eating.
By Paul Shindman, World Israel News
A team of archaeologists from Tel Aviv University has finally figured out what cave dwellers near Tel Aviv were doing hundreds of thousands of years ago with carefully shaped balls of rock.
Tel Aviv has a deep culture of basketball and soccer, but the baseball-sized rocks were tools used for something more basic – cooking.
Found in caves and archaeological sites across the region and as far away as China, the balls from the Paleolithic stone age had puzzled researchers as to their purpose.
The stone balls in Israel were discovered at a site called Qesem Cave some 14 kilometers east of Tel Aviv, an ancient dwelling place unearthed during a road construction project in 2000. The archaeological site has produced a treasure-trove of flint tools, human remains and other clues into the daily lives of the people who lived there 200,000 to 400,000 years ago.
In findings published last week in the San Franciso-based online scientific research journal PLOS ONE, the team led by researcher Ella Assaf reported how evidence showed the hand-sized rocks were used to break open the bones of large animals to extract the bone marrow.
The discovery of some 30 round rocks, what the team called SSBs – stone shaped balls – had puzzled scientists as to their function. They noted that similar SSBs were found in the Middle East dating much earlier to between 500,000 and 1.4 million years ago, but previous thinking was that their use had fallen out of fashion 100,000 years before cave dwellers appeared in Israel.
At the Qesem site evidence was found that the cave dwellers there knew how to use fire and the team examined the surfaces of the balls for any microscopic residue that survived through the millennia. They analyzed the surface marks to determine what they had been used for, noting that the balls weren’t perfectly round but had ridges they suspected were used for scraping the bones after they had been broken open.
“Use-wear and bone residues on 10 SSBs indicate that the inhabitants of Qesem Cave favored the use of shaped, somewhat angular, stone balls made of carbonate rocks to crush fresh animal bones to access fat: mostly marrow and possibly grease too,” the report said, noting that the ancient residents were constantly recycling the tools that they used.
Assaf recruited colleagues at Madrid’s Unversidad Autonoma who made their own similar shaped rock balls and tested them in a lab by smashing animal bones, then analyzing the residue and the wear and tear. The Spanish team found their tests results were similar to the ancient rocks discovered in Israel, Ha’aretz reported.