NEW YORK, NEW YORK—According to a statement released by New York University, stone tools recovered in France from the Neanderthal site of Le Moustier in the 1960s have been reexamined by an international team of researchers. The team, led by Patrick Schmidt of the University of Tübingen, detected traces of ocher and bitumen on several of the scrapers, flakes, and blades. “We were surprised that the ochre content was more than 50 percent,” Schmidt said. “This is because air-dried bitumen can be used unaltered as an adhesive, but loses its adhesive properties when such large proportions of ochre are added,” he explained. The researchers then tested liquid bitumen and bitumen mixed with various levels of ocher. They found that a mix made up of 55 percent ocher and 45 percent bitumen was just sticky enough to hold a stone tool and yet not stick to the hands, making it a suitable handle. Team member Radu Iovita of New York University said that microscopic examination of the ancient tools revealed wear on the sharp edges from use on other materials, and bright polish on other areas of the tools, where they may have been abraded by the movement of the tool within a grip made of ocher and bitumen. “Compound adhesives are considered to be among the first expressions of the modern cognitive processes that are still active today,” Schmidt concluded. Read the original scholarly article about this research in Science Advances. To read about the earliest known piece of cord, go to "Twisted Neanderthal Tech."