>>41296589Fossils are fossils because they're preserved with rock infusing itself into the empty spaces in bone and mineralizing the tissue. I think that when you revive them, that rock gets incorporated into their existing form and ends up altering them in some way. You never truly turn them into the way they used to be, but you get a sort of hybrid of what they once were with the remaining parts just being filled in with the rock.
Although, gen 8 fossils seem to mess that theory up, I'm wondering if that's due to their incomplete forms. Hence why they're so fucked up.