For two million years the rock lay undisturbed, containing a hidden secret and perhaps one of the most important archeological finds ever.
For another few years, the rock lay undisturbed in a laboratory, until a technician noticed a tooth sticking out of the back.
Opening it up, the South African scientists discovered what they call the most complete skeleton yet of an ancient relative of man, hidden in the rock which was first excavated from an archaeological site three years ago.
University of Witwatersrand palaeontologist Lee Berger said the remains of the juvenile hominid skeleton, of the ‘Australopithecus sediba’ species, constitute the ‘most complete early human ancestor skeleton ever discovered.’
The remains are thought to be around two million years old, and add a few years for the time that the three-foot-wide rock lay unnoticed in the laboratory.
The technician, Justin Mukanka, said: ‘I was lifting the block up, I just realized that there is a tooth.’
It was then scanned to reveal significant parts of an A. sediba skeleton, dubbed Karabo, whose other other parts were first discovered in 2009.