Those look like chisel marksInteresting piece, it's a lot thicker than I first thought also.
It's probably just the Pareidolia kicking in though it sure looks like a game animal toting a set of antlers.
(Just below the drilled hole)
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What is the theory on the grooves? So the cordage would lay flatter? Would that really be worth the effort? If it was wear you’d think the hole would be oblong