Geologic Time Scale Crossword

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