Across
- 3. Fossils of marine organisms in Mississippi suggest the state was once covered by this
- 4. A fossil used to date and correlate strata across regions
- 6. What fossils of aquatic plants in deserts suggest once covered the area
- 7. Higher oxygen levels in Earth’s past allowed insects to grow this size
- 10. Similar bone structures between fossils and modern species show this
- 12. Fossil record provides evidence that organisms share this
- 13. Modern marine mammals that evolved from land-dwelling ancestors
- 16. The softer layer beneath the lithosphere where plates move
- 17. Supercontinent evidenced by Glossopteris fossils
- 18. Believed to have caused the extinction of the dinosaurs
- 19. A mass extinction is an abrupt loss of this in the fossil record
- 21. Number of major mass extinctions in Earth’s history
- 22. Currents in the mantle that drive plate tectonics
- 23. Forces that can lift, fold, or change strata
- 24. The law stating that in undisturbed rock layers the oldest rocks are on the bottom
Down
- 1. The type of pattern shown in fossil sequences over time
- 2. Process at convergent boundaries where one plate sinks under another
- 3. The type of rock most likely to preserve fossils
- 5. Differences in traits that allow species to evolve
- 8. Period at the end of which dinosaurs went extinct
- 9. The theory that continents move over Earth’s surface
- 11. Earth’s crust and rigid upper mantle
- 14. Layers of rock that represent specific intervals of geologic time
- 15. Large moving sections of Earth’s lithosphere
- 20. The process by which organisms change over millions of years