\begin{definition}[Definition:Lebombo Bone]
The '''Lebombo bone''' is a baboon's leg bone bearing $29$ notches which were carved into it between $33 \ 000$ B.C.E. and $42 \ 000$ B.C.E.
It is the earliest known instance of a system of tally marks.
It was found in {{WP|Border_Cave|Border Cave}} in {{WP|South_Africa|South Africa}} in the {{WP|Lebombo_Mountains|Lebombo mountains}}, near the border with {{WP|Swaziland|Swaziland}}.
Various untestable hypotheses have been raised concerning this artefact, notably that it was created by an early African woman to count the days between her menses. However, as the bone appears to be broken at one end, it is possible that the count of $29$ is not the complete set of notches that were originally carved.
\end{definition}