1. Relative Age of Fossils
SPI
Relative Age of Fossils
Notes
Science
Create an 8 flap foldable.
Outside flap – label type of fossil
Inside flap - describe type of fossil.
Inside of foldable (center of paper) – draw each type of fossil and label the fossil.

2. Relative Age of Fossils
SPI
Relative Age of Fossils
Notes
Science
What Are Fossils?
Fossils are the preserved physical remains of deceased organisms that are at least 10,000 years old
NOTE: Most organisms DO NOT become fossils after death
NOTE: The formation of fossils is a RARE event
How Are Fossils Formed?
Watch this amusing video: Link: Video: How Fossils Are Made
Primate Fossil:
47 million years old
Whale Fossil:
25 million years old

3. Relative Age of Fossils
SPI
Relative Age of Fossils
Notes
Science
8 Types of Fossils
A) Fossils In Rocks
E) Frozen Fossils
B) Fossils In Amber
F) Trace Fossils
C) Petrified Fossils
G) Mold/Cast Fossils
D) Fossils In Asphalt
H) Index Fossils

4. Relative Age of Fossils
SPI
Relative Age of Fossils
Notes
Science
A) Fossils In Rocks
Found in sedimentary rock
An organism died –was covered with mud, dirt, sand, ash, etc.
Later the mud, dirt, sand, or ash became sedimentary rock

5. Relative Age of Fossils
SPI
Relative Age of Fossils
Notes
Science
B) Fossils In Amber
Tree sap fell on a small organism, enclosed it, & killed it
Over time the sap hardened into amber
The amber became covered with mud, dirt, sand, ash, etc.
Example:
Insects In Amber

6. (Also known as petrifaction)
C) Petrified Fossils
Organism died- then was covered with mud, dirt, sand, ash, etc.
The structure of the organism was replaced with minerals
(Also known as petrifaction)
Sometimes when wood is buried, groundwater will flow through the sediment and deposit minerals in the cells of the wood.
The wood rots away & the minerals remain in the shape of the tree.
Example:
Petrified Wood
Example:
Petrified Wood

7. Notes Science Relative Age of Fossils D) Fossils In Asphalt
SPI
Relative Age of Fossils
Notes
Science
D) Fossils In Asphalt
Animals fell into tar pits, were trapped, and died
The asphalt hardened preserving skeletons, shells, teeth, etc.
Saber Tooth Tiger Fossil
(From La Brea Tar Pits, California)

8. Frozen Baby Mammoth Frozen Baby Mammoth
E) Frozen Fossils
Animals died in a cold climate region and were frozen.
The cold temperatures preserved both soft and hard parts.
Many mammoths became frozen during the last ice age.
Frozen Baby Mammoth
(From Siberia, Russia)
Approx. 42,000 yrs old
Frozen Baby Mammoth
(From Siberia, Russia)
Approx: 40, 000 yrs old

9. Notes Science Relative Age of Fossils F) Trace Fossils
SPI
Relative Age of Fossils
Notes
Science
F) Trace Fossils
Are impressions or “traces” left by plants and animals.
Can be simple tunnels or burrows in the mud.
Can be footprints or imprints in the mud etc.
(Also called ichnofossils)
Trace Fossil Dinosaur footprints
Trace Fossil
Imprint Of A Fish

10. Relative Age of Fossils
SPI
Relative Age of Fossils
Notes
Science
G) Mold/Cast Fossils
In sediment, ground water may dissolve shells, leaving a shape called a mold.
Sometimes the shell dissolves and is replaced by minerals, leaving behind a mineral cast of the fossil.
Mold Fossil
Cast Fossil

11. …we call these index fossils
H) Index Fossils
Some fossils are commonly found at certain strata levels.
across large geographic areas.
…we call these index fossils
Are used to estimate the rock’s age.
(A.K.A. relative dating)
Example:
Trilobite fossils
Example:
Ammonite fossils