Final answer:
Dinosaur fossils are formed through the process of burial and mineralization, which involves compaction and cementation. Compaction reduces porosity by bringing grains closer together, while cementation occurs as minerals precipitate into pore spaces.
Step-by-step explanation:
The vast majority of dinosaur fossils are formed through a process involving burial and some form of mineralization. Sediments need to be buried so that the lithification process can take place. This involves two steps: compaction and cementation. Compaction brings the grains closer together by reducing porosity, while cementation occurs as minerals precipitate into the pore spaces, acting as a glue that holds the sediment together.