Mass Extinction

123456789101112131415
Across
  1. 2. Wiped out about 50 to 80 percent of all __________ on land.
  2. 5. In the Cretaceous extinction these were a hardest hit organism.
  3. 6. The Cretaceous period ended and began the __________ period.
  4. 7. In the Devonian extinction these were a hardest hit organism.
  5. 10. Extinction that hasn't happened yet.
  6. 11. The Permian extinction was the ___________ mass extinction in Earth's history.
  7. 12. ______________ continents probably led to massive volcanic activity.
  8. 15. Extinction that was 440 Million years ago.
Down
  1. 1. Started the transition from water to land.
  2. 3. Extinction that was 250 Million years ago.
  3. 4. Extinction that was 360 Million years ago.
  4. 8. A ______________ hit the Earth and made the Cretaceous extinction.
  5. 9. Extinction that was 200 Million years ago.
  6. 13. Extinction that was 65 Million years ago.
  7. 14. _________ gases and dust hid the Sun.