Across
- 5. most marine life thrived here in this period
- 7. there was mostly plants, ferns, and the first conifer and ginko trees
- 8. in horizontalsedimaentary rock layers the oldest layer is at the bottom and the youngest at the top
- 12. real age in actual years its either based on fossils or on radioactive decay
- 14. relative order of past events without necessarily determining their absolute age
Down
- 1. the change in Earth's crust during geological time
- 2. tells about the history of the earth
- 3. the super continent Pangea split up
- 4. billions of years since the Earth started developing
- 6. the age of a certain rock layer
- 9. preserved remains or traces of living things that are formed when living things die and are buried by sediments
- 10. hard-bodied brachiopods, which resembled clams; and arthropods
- 11. the numeric age of a layer of rocks or fossils
- 13. most marsupials and modern day rodents and cats
- 14. parallel layers arranged one on top of another