"We experimented by hitting and dropping similarly shaped pebbles in different ways to see which produced the breakage characteristics of the pebbles found in the assemblage," study author Claudine Gravel-Miguel of Arizona State University, told Seeker.
"The pebbles were broken by snapping them on a rock or by hitting their flat surface with a bigger rock," she added.
The "killing" of inanimate objects to break their symbolic power is a well known ritual associated with some prehistoric human burials. Until now, it was thought that this practice only appeared in the Neolithic period in Central Europe, about 8,000 years ago.
"If our interpretation is correct, we've pushed back the earliest evidence of intentional fragmentation of objects in a ritual context by up to 5,000 years," Gravel-Miguel said.
The new evidence may indeed be the earliest instance of ritualistic breakage of artifacts, dating to somewhere between 11,000 and 13,000 years ago.
"At that time people in Liguria were hunter-gatherers but also fishermen. Isotopes analysis of another, much older, burial indicate that 20-25 percent of the food had a marine origin," Roberto Maggi, at Genoa University, told Seeker.
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All of the pebble fragments analyzed by the researchers were missing some matching pieces. They suggest that the missing halves were kept by the living as talismans, souvenirs or mementos, to symbolize lasting bonds to the deceased.
"They might have signified a link to the deceased, in the same way that people today might share pieces of a friendship trinket, or place an object in the grave of a loved one," Riel-Salvatore said.
"It's the same kind of emotional connection," he added.
According to the researchers, archaeologists usually overlook these objects.
"If they see them at a site, they usually go 'Oh, there's an ordinary pebble,' and then discard it with the rest of the sediment," Riel-Salvatore said.
Now the finding could have important implications for research at other Paleolithic sites where pebbles have been found.
As Gravel-Miguel said, "We demonstrated that studying seemingly mundane objects found around burials, instead of focusing only on the burials themselves, can give a new perspective on how people dealt with death in the deep past."
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