Answer:
shells, bones, and teeth
Step-by-step explanation:
Fossils are organic remains of a living creature that existed millions of years ago. This rests tend to attache to sedimentary rocks. Fossil formation occur after a body has been buried, the soft parts such as organs, muscles, fur, skin, guts, etc are usually eaten by scavengers organisms, or they tend to decompose after the death.
On the other hand, the hard parts such as skeleton, shell, and bones are not eaten by any animal or decomposed by any microorganisms present in the soil. Then, the sentiment will begin to cover the remains, after a while, the sediment would solidify becoming a rock with the form of the bone or hard remans such us shells or teeth that is beneath it.