The dating techniques I'm aware of use U238 or U234, not U235, and none of them is terribly suitable for the purpose you mentioned. [This should not be meant to imply that there are no such dating techniques available, as I'm hardly an expert here.] Dating rocks, sure. Dating bones? Not likely. The best one I can find, uranium-thorium dating, measures the proportion of uranium-234 to thorium-230 and works well with corals (due to the property of uranium being relatively water soluble but thorium being insoluble in water) but not with land-walking bones.