Fossils are the remains or traces of past life.
2. Preserved bones and tracks are two types of fossils. Describe three other types of fossils.
There are many different types of fossils. Bones, teeth, shells, skin, trails, plants, bacteria, burrows, impressions of leaves or feathers, feces, whole organisms trapped in amber or ice, amongst others, can all form fossils.
3. Which is most likely to fossilize: a clam or a jellyfish? Explain your answer.
The hard shell of a clam is more likely to fossilize because it is more resistant to biological and environmental destruction. For this reason, teeth, bones and other hard parts of organisms are much more numerous in the fossil record than soft tissues.
4. Why is a quick burial helpful in the fossilization process?
Rapid burial protects a dead organism from destruction by biological and environmental factors.
5. In what type of rock would you most likely find fossils? Circle the best answer below.
c. Sedimentary. Sedimentary rock is made up of layers of hardened sediments that accumulate over time. The sediments protect the remains of organisms from biological or environmental destruction. Fossils are unlikely to survive the heat and pressure involved in the formation of igneous and metamorphic rocks.
6. Once a fossil has been formed, it still might not become part of the fossil record. Describe two natural processes that might destroy the fossil.
Answers include:
If a fossil is buried by a lot of sediment, it may become flattened or distorted beyond recognition.
Once buried, the fossil and surrounding rock might undergo extreme pressure and heat, and the fossils could melt.
Once fossils are formed, they might be washed away by streams, moved by glaciers, carried by scavengers, or caught in rockslides.
Weathering by wind, water, and sun can destroy a fossil by wearing it away.
7. Of all the organisms alive today, what percentage do you think will eventually become fossils? Circle the best answer below.
a. Fewer than 10%. Many organisms are soft-bodied and do not fossilize well, and others are destroyed by environmental or biological forces before they can be fossilized. Still others die in environments such as rain forests or rocky shorelines where they wash away or rapidly decompose.