Geologic Time Scale Crossword

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Across
  1. 4. change of organisms over a long period of time
  2. 5. era we are living in now
  3. 6. organisms fail to survive & completely die out
  4. 8. period where flowering plants evolved
  5. 10. era in which life first appeared
  6. 12. dominated the Mesozoic era
  7. 13. period marked by appearance of first bird
Down
  1. 1. large impact space stone believed to cause extinction of dinosaurs
  2. 2. model of the history of life on Earth
  3. 3. era where 1st land plants and fish appeared
  4. 7. appeared during the Cenozoic era
  5. 9. animals with backbone
  6. 11. era known as age of the dinosaurs