Fossils Flashcards
0
Q
Name three ways fossils form.
A
Gradual replacement by minerals, from casts and impressions and preservation where decay doesn’t occur.
1
Q
What is a fossil?
A
The remains of organisms found in rocks.
3
Q
What is gradual replacement?
A
Where things like teeth, bones and shells are replaced by minerals that leave a rock-like substance, creating a fossil.
4
Q
How do casts and impressions create fossils?
A
When an organism is buried in a soft material like clay, the clay hardens as the organism decays and leaves a cast/impression of the organism.
5
Q
How does preservation create fossils?
A
Areas or materials, like glaciers where it’s too cold for decay microbes to work, stop organisms from decaying.
6
Q
What do fossils show?
A
How organisms have evolved over time.
