1. Early Earth History Sci 4.2

2. Question 1

3. Precambrian time 1 st 4 bil. years Few rocks older than 3.5 bil. due to erosion and remelting

4. Question 2

5. 1st organisms were single celled cyanobacteria: (blue-green algae) did photosynthesis Produced stromatolite fossils

6. Question 3

7. photosynthesis In chlorophyll, CO 2 is taken apart A few types of Cyano- bacteria CO 2 light C + O 2 In stratosphere O 2 UV light O 3 (ozone layer)

8. Question 4

9. Invertebrates: Animals without backbones Appeared late Precambrian Ediacaran fauna

10. Question 5

11. Paleozoic era 1 st animals with hard parts 1 st insects 1 st Vertebrates Shallow seas

12. Dunkleosteus a.k.a. Bonefish

13. Question 6

14. Amphibians: Lungs, must lay eggs in moist places May have evolved from fish like Had both lungs and gills

17. Question 7

18. 1 st Insects Appeared about same time as amphibians

20. Reptiles: Evolved from amphibians Have scales to retain water Eggs have protective membrane

21. Question 8

22. Appalachian/Atlas mtn.s Pangea forms in late Paleozoic Breaks apart in early Mesozoic

23. Question 9

24. End of Paleozoic 90% marine species became extinct 70% land “ “ “ Pangea and glaciers formed

25. Question 10

26. Organize in order of appearance on earth Invertebrates Vertebrates (fish) Amphibians (and insects) Reptiles Amphibians (and insects) Vertebrates (fish) Reptiles Invertebrates