[Teflonic]

Wrap some rope around one and sling it and the archaeologist who gets hit with it will realize real quick what they were used for.

That's my first thought as well, rope or sinew. Those binding grooves make their use completely obvious to anyone with common sense - especially when you consider that weapons in every society in history have always been the most technologically advanced objects produced at the time.

[publius911]

Wrap some rope around one and sling it and the archaeologist who gets hit with it will realize real quick what they were used for.

Not bloody likely.
Even primitive man was not an idiot.
Spend weeks engraving a perfect sphere to kill the Sabre-tooth Tiger, when there are a gazillion free rocks scattered everywhere?