Dr. Hudson is holding what appears to be an arm or leg bone & thinks it might go in the tail of the Brontosaurus skeleton.
Where did this man study anatomy? Personally I'd say there is no way that 'little'* bone goes with that skeleton.

* Little in contrast to the Brontosaurus.

George the dog takes up a fossil bone & buries it.
Fossilized bones are rocks & usually heavy & I can't imagine any dog being interested in picking one up & burying it.

At the end of the movie, Susan is on a ladder & it is rocking back & forth. At first the rocking seems to be because of her shifting her weight, but at the end it's rocking independently of her movements. It's also swinging over too far to believably swing back.

Susan climbs on top of the Brontosaurus skeleton & it collapses.
Fossil bones are rock. The Brontosaurus (or Apatosaurus as they call it now) has big bones & these things are heavy. The structures museums use to hold dinosaur skeletons together have to support a lot of weight. While I wouldn't say that it's impossible for this situation to occur, I would say it is highly unlikely.