1. Fossils

2. What are fossils?
The remains, imprints or traces of an organism that lived long ago.
Preserved in rock.
Typically sedimentary rock
Must be buried quickly
Types of fossils:
Molds
Casts
Carbonaceous film
Petrified remains
Original remains
Trace fossils
Hard parts decay leaving behind a cavity in the rock
Formed when the mold becomes filled
Thin film of carbon forms outline on rock
Minerals replace the original organism
The actual organism is preserved
Evidence of organism activity (footprint)

4. How were entire organisms preserved?
Original remains can be preserved in different materials.
Ice
Tar
Amber
Glaciers
La Brea Tar Pits
Tree sap

5. Otzi the Iceman
Called Otzi, because found in the Otzzi Alps near Hauslabjoch on the border between Austria and Italy
Look at how, when and why
A frozen organism does not decay because most bacteria can’t survive freezing temperatures.

6. Oldest human found
Omo
Pics of Skulls

7. Different types of fossils
Mummification-Fossilized remains of an organism found in very dry places
Gastrolith-Fossilized stone from the digestive system of a dinosaur (stomach stone)

8. Diff types of Fossils Coprolite-fossilized dung or waste
Petrification-Minerals replace organic material
Imprint-carbonized impressions of plants and fish

9. Index Fossils Organisms that lived during short spans of geologic time
Found in rock layers in different areas of the world. This indicates that rock layers formed during the same period of time.

10. What are fossil fuels?
Raw fuel that comes from the remains of once living organisms
Solid
Liquid
Gas
Coal
Petroleum or Oil
Natural Gas or methane

11. Why do scientists study fossils?
Clues to the past
Global changes & regional changes
Environmental
Natural disasters
Climate change
Geologic
Evolution

12. How can relative age of rocks be determined?
Using the law of superposition relative age can be determined
Relative age is comparing one objects age to another.
If there are three layers
Top is youngest
Then middle
Bottom is oldest
Index fossil is always found in a particular layer

13. How is absolute age determined?
The specific age of a rock or fossil
Uses radioactive decay
Half-life is the amount of time it takes for ½ of the mass of an element to decay into, more stable, element.
The rate of decay can be measured
Particular elements have a constant rate of decay
Carbon-14 dating for living things
Not always 100% accurate!
Half-life

14. Review of geologic time scale.
Precambrian
Paleozoic
Mesozoic
Cenozoic
Era
Periods
Epochs
Cambrian
Ordovician
Silurian
Devonian
Carboniferous
Permian
Triassic
Jurassic
Cretaceous
Tertiary
Quaternary
Paleocene
Eocene
Oligocene
Miocene
Pliocene
Pleistocene
Recent

15. What is a fossil??? Play palentologists studying fossils
Play palenotologists studying tracks and traces

16. The End!