Detailed Instructions: In this task, you are given a paragraph, and your job is to generate comma-separated entities present in the given paragraph. Generate entities from a given passage in such a way that (i) they are present in the paragraph, (ii) they are non-duplicate, (iii) they underwent a state change during the process. Avoid creating entities that (i) aren't present in the process paragraph and (ii) aren't significant. 
Q: Animals and plants die in soft soil or mud. Sediment builds up over the remains. The remains decompose, leaving only trace amounts. The remaining parts over the years are replaced with mineral. A fossil is formed. 
A:
animals ,plants ,sediment ,remains ,mineral ,fossil 