Consequences be damned, if I could make Jurassic Park, I would.
So even if you wanted to I don't think you could. However, a mammoth for instance might be possible to clone.
Also: life uh... uh finds a way.
It's not happening unless there is some natural mechanism that increase that half life of DNA quite a bit, and is stable for millions of years. Otherwise we would need the DNA to leave some byproduct that we can detect.