* How sedimentary rocks form: Sedimentary rocks are formed from layers of sediment (like sand, mud, or the remains of organisms) that are compacted and cemented together over time.

* Preservation: The process of forming sedimentary rocks can preserve the hard parts of organisms (bones, shells, teeth) or even sometimes their soft parts under the right conditions.

* Examples: Fossils are commonly found in rocks like sandstone, limestone, and shale, which are all sedimentary rocks.

While fossils can be found in other rock types, it's much less common:

* Igneous rocks: Formed from molten rock (magma or lava). The intense heat would destroy any fossils.

* Metamorphic rocks: Formed when existing rocks are transformed by heat and pressure. The process can distort or destroy fossils.

Let me know if you'd like to learn more about how fossils form!