Sediment can bury remains and later compact/cement into sedimentary rock. Heat and melting usually destroy delicate evidence, which helps explain why fossils are most common in sedimentary rather than igneous rock.

The model has a domain of validity. Explain its assumptions before using it in a changed context, then compare your prediction with evidence.

• Rapid burial and preservation can leave remains or traces in rock. The fossil record is evidence of past life with large preservation gaps.
• Most organisms never fossilize. Absence from the record alone is weak evidence of absence.