1. Fossils

2. Footprint left by a dinosaur
What are fossils?
Fossils are the remains of a prehistoric animal or plant preserved in sedimentary rock.
Types of fossils:
Actual bones or remains
Imprint or mold
Cast (made when sediments fill in fossil)
Track or trail
Mold a cephalopod
Remains of a trilobite
Footprint left by a dinosaur

4. What are the odds? Poor Good Poor Good Tree growing in a swamp
Horse drowned in a
river flood plain
Good
Jellyfish in the ocean
Poor
Small animal caught
in a tar pit
Good

5. Studying Fossils Paleontology--The study of fossils before man.
Geologic Time Scale--Rocks are placed in order from oldest to youngest.

6. Studying fossils cont’d
Law of Superposition--Younger rocks lie on top of older rocks.
Relative Age--Age of a rock when compared to other rocks.
Geologic Column--Arrangement showing rock layers in the order they were formed.

7. Division of Time Era--The longest division of time.
Period--Subdivision of an era.
Epoch--Smallest division of time. The era divided in epochs is the Cenezoic Era.

8. Precambrian The Precambrain Era has the most primitive life forms.
Earliest era
Longest era
Fewest fossils, all invertebrate species
Only era with no periods or epochs
Areas where Precambrain rock can be found
Image sources: nasa.gov and nationalatlas.gov

9. Paleozoic The Paleozoic Era has the first vertebrates.
Plant life began to develop on land
First animals begin to appear on land
Area where Paleozoic rock can be found
Image sources: nasa.gov and nationalatlas.gov

10. Mesozioc The Mesozioc Era is considered era of middle life.
Three periods: Jurassic, Triassic, and Cretaceous
Era during which the dinosaurs lived
Area where Mesozioc rock can be found
Image sources: nasa.gov and nationalatlas.gov

11. Cenozoic The Cenozoic Era is the current era during which we live.
Shortest era
Era with the most fossils
Area where cenozoic rock can be found
Image sources: nasa.gov and nationalatlas.gov