Could the cups be formed by the shaping of the handheld part of a teardrop shaped hand axe? I have looked at some just found in Kenya on the BBC science site and it 'struck' me. The haphazard placing of them has to point to some practical use and the decoration? well they must have had a lot of spare time on their hands, obviously.
This also seems to explain the size of the cups as they all look to be ground out to the same diameter and depth which would be the case if this was their function.
Also they must have been caused by rotation as chipping these things out would have caused uneveness in formation.
Looking forward to being 'shot down'.
Rod Axeman. :<a href=\'h