Picked this from an old timer's collection: no provenance at all. I don't see any peck marks, any indication this piece was worked. Yet, it does seem to have a somewhat distinct 'rim' and certainly has an unnatural looking bowl shape.
Well, dog, it's not stable at all. The slightest pressure on one side causes it to rock; the base is rounded. Makes me suspicious...
But.....if the user placed in into soft soil or a carved out tree stump... that would stabilize it. I am definitely 50-50 sure that I am doubtful about this item.