Only overcup I've ever seen, the cup completely covered the acorn. I wanna see the leaf if ya got a pic. Also, that looks like a ridge he's sittin on. If it came from there, it'd be the first overcup I've ever seen that grew more than 20ft. away from a swamp.
No swamp nearby.... I found abunch of em walking a ridge... I will have to get pictures of the leaves and tree itself next weekend but all were identical to this one size color and cup.