Earth and space

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Across
  1. 6. time period where 96% of marine species disappeared
  2. 8. part of the Mesozoic era
  3. 10. the outcome of the movements of tectonic plates
  4. 11. the remains of an organism that have been preserved are?
  5. 12. a naturally occurring substance
  6. 13. an example of this is lighting
  7. 17. time period where 70% of marines species disappeared
  8. 18. experts in the study of fossils
  9. 19. many animals couldn't _______ to changes in there environment
  10. 21. time period where about 50% of animal species disappeared
Down
  1. 1. one of the last steps to make a fossil
  2. 2. the disappearance of all individuals belonging to that species
  3. 3. a group of living organisms
  4. 4. this causes the animal remains to be resurfaced and discovered
  5. 5. this causes the creation of a fossil
  6. 7. layer that is made up of sedimentary deposits
  7. 9. disappearance of dinosaurs
  8. 14. a type of rock formed by the deposition of material
  9. 15. long period of time
  10. 16. the original organism's tissues
  11. 20. the earth spins around the ____?