I'm guessing, but looking at the circular pattern of the wear / weakness, etc I'd guess it got stuck in some machine and just was worn down.
OK, Meow was thinking something like that too. It caught Meow's eye as it has such steamrollered devices both obverse and reverse.
very interesting wear. If you think about it, just look at this section. If there was grease on the die, then wouldn't the wreath section be much weaker on the upper half as it is the lower half? Then look at the top of the letters QUARTER DOLLAR versus the lower half. The upper parts are smushed, deformed, etc. Then add to it, this wear/deformed "pattern" is in a "distinct" circular pattern around the coin. Plus it's 29 years old and essentially damage is unlimited.
Odd that the wings stood up better than the lettering. Must be the bulk of the metal forming the wings helped the wings keep its shape.
Yes, the lettering is not continuous blobs of metal. The metal has empty spots to move/get deformed into. The wings are continuous blob of metal.
Guess Meow will keep it for a short while to study it more, but it will be put back into the wild eventually. Too bad it was PMD, it would have been a cool error coin otherwise.
Meow has figured out in what direction it was spinning when damaged. From the point of view looking at the reverse, it was spun counter clockwise. The top right tip or the wings, and the bottom of the left wing are ramped up much more that its other counterparts. So when spinning the right tip gets the initial hit, then rotated off the right wing to hit the bottom tip of the left wing next. Meow likes the way it feels. It must have been rubbing on a smooth surface for a long time, as it is not rough in any way; And there are no notable scratches on the affected areas. It feels good in the paw.