Many moons ago I wrote a short post on the pedal unguals of hadrosaurs and in it I mentioned jsut how similar they are to those of the hand. To prove that point, here is a hadrosaurs hand that can be contrasted the the foot from the link above. It’s worth remembering that for a long time the ornithopods (that is hadrosaurs and igunaodontians) were considered proper bipeds and not the facultative bipeds we think of them now.
Obviously it’s not like people *didn’t* think about this when they came up with the hypothesis, but one does have to wonder a bit quite what they did think these hands were good for if they weren’t walking on them, especially when they are so obviously similar to the feet which were being walked on. Swimming doesn’t really fit or the toes would be longer and more widely spaced out, and I’m not aware of any other hypotheses that were floating around. Even so, it’s remarkable how some things cling on in the collective conciousness and I still come across the idea that hadrosaurs were semi-aquatic though I think this bit the dust in the 60s if not before.