Unit 12 Change Over Time

Unit 12Change Over Time

How the fossil record is used to attempt to show evidence

of animals changing over time.

Seasons can show change over time

Skeleton of a dog.

Skeleton of a bulldog.

Law of Superposition

Older

Newer

Coelacanth as a fossil

Coelacanth alive today.

Sharks alive today

Sharks preserved as a fossil

Other “living” fossils

• Uniformitarianism doesn’t explain how we find soft-tissue animals in the fossil record.

• Slow deposition over time simply takes too long

• Soft bodied animals like jellyfish would be either rotted away or eaten by scavengers.

• Catastrophism can explain how a jellyfish can be fossilized.

Some thoughts….

In order for a fish giving birth to fossilized, it has to be covered instantly with sediments, at the moment it occurs.

In order for a fish eating a fish to fossilized, it has to be covered instantly, at the moment it occurs.

This is a trilobite and the tracks it made just prior to be covered up by a massive and sudden amount of

sediments!