South Africa-based American explorer and scientist Lee Berger says he has discovered "for the first time, a non-human that makes meaning-making symbols, carved into the wall, above graves of its own hundreds of thousands of years before humans did." Some experts however remain "skeptical" of his theory, "it would be exceptional and it's something that requires exceptional evidence" says Stratford, Professor of Geoarcheology at Witwatersrand University, home of the hominide fossil vault "where all the fossils hominide from the cradle of humankind lay to rest". IMAGES AND SOUNDBITES ARRANGED IN SEQUENCES