Question

In what type of rock do fossils usually form in?

Answer 1

Sedimentary rock

Explanation:

Fossils typically occur when an animal dies in mud or silt. This protects it from predators and weathering and will eventually cover it in sediments. Eventually the layers of sediment will undergo lithification - the process by which solid rocks are formed from pressure, and all the organic material that's been petrified - bones - form together with the rock.

Fossils typically don't form in metamorphic rock due to the high levels of pressure and temperature required to form them - any fossils that may be present are generally destroyed. Igenous rocks almost never form fossils as they're formed from molten magma, which also destroys the fossil.