1. Sci. 3-5 Times Marches On Pages 73-77

2. A.The history of the Earth is recorded in rock layers 1) Earth is about 4.6 billion years old.

3. B.The geologic time scale- a scale that divides Earth’s 4.6 billion year history into distinct intervals of time.

4. C. Eons- largest division of time 1) Hadean Eon 2) Archean Eon 3) Proterozoic Eon 4) Phanerozoic Eon

5. D.Eras- the eons are divided into eras.

6. 1)Phanerozoic Eon has 3 eras. a)Paleozoic- no land animals at the beginning, mostly water animals, toward the end- some land animals and amphibians and insects. b)Mesozoic- Age of the Reptiles- Dinosaurs, some small mammals and birds c)Cenozoic- recent life- Age of mammals, humans show up here.

7. E. Periods- Eras are divided into Periods. 1)Paleozoic has 7 Periods. 2) Mesozoic has 3 Periods. 3) Cenozoic has 2 Periods.

8. F. Epochs- Cenozoic has the periods divided into epochs because we have some much information about this Era.