1. Ch 9 View From Earth’s Past
Time Scales
Fossils
Terms
Time Periods
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2. The mass extinction at the end of this period led to abundant new life forms in the Mesozoic and Cenozoic Eras
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3. Permian Period
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4. How many billion of years ago did the Earth form?
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5. 4.6 billion
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6. The era of time that began 65 million years ago
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7. Cenozoic Era
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8. How many eons is geologic time divided into?
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9. 4 eons
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10. What is the first period of the Mesozoic Era?
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11. Triassic Period
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12. The impact hypothesis states that an _____ crashed into Earth, making the dinosaurs extinct.
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13. Asteroid
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14. What are the most common Precambrian fossils?
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15. Cyanobacteria
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16. Relative ages of sedimentary rock all around the world created the _____ column
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17. Geologic column
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18. True or False: the mass extinction at the end of the Permian Period led to abundant new life forms
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19. True
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20. What natural forces can destroy fossils?
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21. Tectonic Activity: Volcanic activity, folding, faulting, and erosion.
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22. What is the longest unit of geoligic time?
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23. Eon
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24. What is the gradual development of organisms from preexisting organisms?
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25. Evolution
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26. The ordered arrangement of rocks in a column
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27. Geologic column
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28. An episode in which a large number of species became extinct
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29. Mass extinction
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30. What does “Ma” mean?
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31. Millions of years
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32. What period is known as the “Age of Fishes”
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33. Devonian Period
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34. What divisions of geologic time makes up about 88% of Earth’s history?
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35. Precambrian
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36. This era is known as the “age of mammals”
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37. Cenozoic Era
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38. At the end of this period, dinosaurs became extinct.
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39. Cretaceous period
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40. This era is divided into 3 periods:, Triassic, Jurassic and Cretaceous
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41. Mesozoic Era
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42. In a geologic column, where are the oldest rocks?
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43. The bottom
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44. Geologic era that ended about 251 million years ago
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45. Paleozoic Era
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46. What is a geologic period usually names for?
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47. The place where characteristic fossils were first discovered
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48. True or False: Radiometric dating can help determine the absolute age of rocks
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49. True
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50. Dinosaurs were most abundant in this period
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51. Jurassic Period
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