Ishango bone

The Ishango bone is a bone tool, dated to the Upper Paleolithic era, about 18000 to 20000 BC. It is a dark brown length of bone, the fibula of a baboon,^[1] with a sharp piece of quartz affixed to one end, perhaps for engraving or writing. It was first thought to be a tally stick, as it has a series of tally marks carved in three columns running the length of the tool, but some scientists have suggested that the groupings of notches indicate a mathematical understanding that goes beyond counting.

The Ishango bone was found in 1960 by Belgian Jean de Heinzelin de Braucourt while exploring what was then the Belgian Congo.^[2] It was discovered in the African area of Ishango, which was centered near the headwaters of the Nile River at Lake Edward (now on the border between modern-day Uganda and Congo). The lakeside Ishango population of 20000 years ago may have been one of the first counting societies, but it lasted only a few hundred years before being buried by a volcanic eruption.^[3]

The artifact was first estimated to originate between 9000 BC and 6500 BC.^[4] However, the dating of the site where it was discovered was re-evaluated, and is now believed to be more than 20,000 years old.^[5][6]

The Ishango bone is on permanent exhibition at the Royal Belgian Institute of Natural Sciences, Brussels, Belgium.^[7]

^{http://en.wikipedia.org/wiki/Ishango_bone#Mathematical_calculations.3F}