Jerusalem, Jan 20 : Israeli and Italian researchers have discovered that early humans about half a million years ago used stone chopping tools to break animal bones and consume the bone marrow, Tel Aviv University (TAU) in central Israel said on Wednesday. In their study, published in the journal PLOS ONE, researchers from TAU and the University of Rome, in collaboration with the University of Tubingen, Germany, found that the tools were used to break open bones of cattle, fallow deer and gazelles, and extract the nutritious high-calorie bone marrow, the Xinhua news agency reported. Applying advanced scientific methods, the team unraveled the function of 53 tools found at the prehistoric site of Revadim in southern Israel. These tools are flint pebbles with one flaked, sharp and massive edge, probably used by the late Homo Erectus species. The team detected substantial edge damage on many pebbles, as a result of chopping hard materials, and some also showed residues of animal bones. Use of replicas, made from pebbles collected in the area, on the bones of dead animals, led to the same results as in the original pebbles. Such tools, invented in Africa about 2.6 million years ago and used for over 2 million years, were also found in Europe and Asia, with the current research revealing their use. /IANS