1. Fossils

2. What is a FOSSIL?
Fossil = The preserved remains or traces of an organism that lived in the past.
Fossils give clues to:
diversity of living things over history of Earth.
past climate and surface changes on Earth.
changes that have occurred to organisms over time.

3. Types of Fossils
There are different types of fossils based on how they were formed.
The environment they form in also cause them to form different types of fossils.
Types:
Mold
Cast
Petrified
Preserved
Carbonized
Trace

4. Mold Fossil
Forms when sediments bury an organism and the sediments change to rock.
The organism decays, leaving a cavity in the shape of the organism.

5. Cast Fossil
Forms when a mold is filled with sand or mud that hardens into the shape of the organism.

6. Petrified Fossil AKA “Permineralized Fossil”
Forms when minerals soak into buried remains.
The minerals replace the remains, changing them to rock.

7. Preserved Fossil
Forms when entire organism (or parts of it) are prevented from decaying by being trapped in rock, ice, tar, or amber.

8. Carbonized Fossil
Forms when organisms or parts (like leaves, stems, flowers, fish) are pressed between layers of soft mud or clay.
The mud or clay hardens, squeezing almost all of the decaying organism away.
This leaves the carbon imprint in the rock.

9. Trace Fossil
Forms when mud or sand hardens to stone where a footprint, trail, or burrow of an organism was left behind.

10. Fossil Record Millions of fossils have been collected and studied.
The Fossil Record:
gives important info about past life and environments on Earth.
Shows extinction of life forms
Shows when new life forms appear
Certain fossilized organisms could only live in specific environments under particular climate conditions.