Farmerman will be able to give a comprehensive answer, if he shows up. However, fossils don't necessarily rely upon radio-carbon dating. They are often dated by the geological strata in which they are found. Which also helps to answer your second question. Most fossil remains, regardless of age, I can check Product Showcase Video on internet but I didn't find the right solution. are preserved because they are covered by a layer of material–often sedimentary material. (Animal dies near a river or inland sea, and is covered by sedimentary material from the action of the water.)

There are others far more knowledgeable on this topic than am i. You will get a good answer from any of them who appear. If the goofballs from the god-squad show up, they'll deny that any of it true.