Across
- 3. current period
- 7. dating that tells us exact age of rock or fossil
- 8. these lived in the Jurassic period
- 9. age of reptiles
- 10. fossil that tells us the how old the rock is
Down
- 1. fossil footprints or tracks
- 2. dating that compares ages of rocks or fossils
- 4. explosion of life
- 5. loss of 75% or more of organisms
- 6. 88% of Earth's history