The preservation of biomolecules and now actual
tissue in fossilized dinosaur bone is
interesting, some people are already saying that
this means the fossils formed recently and that
geology/paleontology are fundamentally flawed.
Try C-14 dating. If there's any C-14 in this soft tissue, it's younger than
50,000 or so years. If not, then we can be confident it really comes from
the fossil bone (as opposed to, like, forgery being involved).