2. 87% 4.6 Precambrian

4.  Earth was completely molten  No water  No atmosphere  No land  No life

7.  An object the size of Mars crashes into the still molten earth.  Material ejected by the impact went into orbit around the earth.  This material coalesced and formed the moon.

8. bombardment from space

11.  A time of dramatic geological, climatic, and evolutionary change  Divided into 6 periods:  Cambrian  Ordovician  Silurian  Devonian  Carboniferous  Permian

14.  543 Million years ago  Marked the beginning of the Paleozoic Era  A time when most of the major groups of animals first appear in the fossil record.  This was accompanied by a major diversification of other organisms.

15. trilobite

17. invertebrates

19. land plants

21. fish

22. amphibians

23. swamps

24. Swamps

25. swamps

28.  Permian Mass Extinction  Mass extinction 245 million years ago  95% of all marine species became extinct

29. 87% 4.6 Precambrian Cambrian Devonian Permian Swamps

30.  The Age Of Reptiles  Divided into 3 Periods:  Triassic  Jurassic  Cretaceous

32. earliest dinosaurs

34. Swamps

35. first birds

36. earliest mammals

37. Swamps

40.  The Mesozoic Era ended with the extinction of dinosaurs 65 million years ago  70% of all plants, animals, and reptiles perished

41. Swamps

42.  The Age of Mammals  Divided into 2 periods:  Tertiary  Quaternary

43. Swamps

44. mammals thrive

45. Swamps

46. land mammals dominate

47. earliest humans did not arise until approximately 200,000 years ago