[Michael_Michaelangelo]

All evolutionary assumptions aside, this finding would put upright posture at the base of the human family tree, right? This doesn't leave much time for bipedalism to evolve when the supposed human/ape-like ancestor divergence occurred b/w 5 and 8 mya (by some estimates).

[VadeRetro]

We had a thread maybe two months ago about a monkey which went fully bipedal simply as a behavioral adaptation following stomach trouble. OK, its skeleton would not show much effect, maybe eventually some wear-and-tear differences--from this. Nevertheless, I don't think going fully bipedal is that hard if that's all you're doing. If anything, this is further evidence that full bipedalism preceded other changes leading to humans.