Well, first, we know that Jack, Kate, and Locke knew about the skeletons from about the 50's. Also that Jack in secret took the bag with the stones from the male body. Thus leading everyone to believe he will become the next Adam through time travel.
Unless... When Jack and the others were captured, you don't think that they'd leave their pockets unchecked for weapons when they're going to be prisoners, would you? We haven't seen these stones in quite a while, could it be possible that Richard took these stones off Jack, and will later place on the corpse of which ever Lostie he watches die?
Unless someone can think of a time after that the stones were shown that I missed, then this blogs over.