earths history by grayson

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Across
  1. 5. mass disappearance of a species
  2. 8. fossil that has had all nutrients sucked out
  3. 9. record of geologic events
  4. 12. coldblooded animal
  5. 13. a well tested theory
  6. 21. drift of continents
  7. 24. period of time
  8. 25. person who studies fossils
  9. 26. evolving of an organism
  10. 27. lava rock
  11. 28. metro made of dust and ice
  12. 30. absolute number of years sense rock formed
  13. 32. where old rock meets new
Down
  1. 1. fossils found from one time period
  2. 2. the disappearance of an organism
  3. 3. length of time
  4. 4. lower the rock the older it is
  5. 6. half of time needed to decay atoms
  6. 7. the preserved remains of an organism
  7. 10. thin film of carbon on a rock
  8. 11. animal with back bone
  9. 13. hardened sediment
  10. 14. animal with out back bone
  11. 15. trace of an organism that has been fossilized
  12. 16. edge of earths plates
  13. 17. shape of animal
  14. 18. decay of radioactive elements
  15. 19. magma rock
  16. 20. guess at the age of a rock
  17. 22. pure substance
  18. 23. building block of life
  19. 29. a fossil from desolved organism
  20. 31. animal that lives in water and on land
  21. 33. warm blooded animal