Answer: check explanation
Step-by-step explanation:
Fossils can be simply be defined as the remains of a prehistoric plant or animal embedded in rock.
IMPORTANT THINGS TO KNOW ABOUT FOSSILS: from the definition we can deduce three things;
(1). Fossils are remnants of extinct organisms.
(2). Fossils are found in rocks, and fossils found in rock at different era are different from each other.It is worthy of note to know that different species of animals and plants found as fossils change through time.
(3). Fossils are remnants of once-living organisms.
MY CONCLUSION: if I find a fossil of a clamshell, I will conclude that the organism once lived and it became a fossil after it died. After it death, it became a sediment.