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