Soft tissues preserve poorly, which is obvious enough. Hair, if you’re incredibly lucky might show up, displaying the beaver paddle for whatever might be looking at the fossil, but otherwise, that tail can only be extrapolated to be fairly strong due to the numerous large connection points for muscle. There will be screaming matches between scientists to determine who is right about the beaver’s appearance if the fossil is hairless, and the being discovering it is even faintly human-like.