What is this tool used for?

I have a bonus assignment for my history of technology class. I can’t find anyone who has any idea what this tool was used for. The professor even admits he has no idea. Any help would be much appreciated.
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The bottom of the tool has 3 prongs. 2 are stationary and the third rotates by twisting the wood in the middle. Also what ever the person is holding would be parallel with the shaft, not an angle of any kind.