Fossils & Geologic Time

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Across
  1. 2. Fossilized tree sap that preserves insects as fossils
  2. 5. A process that occurs when the organic (living) material of an organism is replaced with minerals and turned into stone
  3. 7. The oldest era whose major life forms include fish insects, amphibians, and reptiles
  4. 9. The unit of geologic time that eons are divided into
  5. 11. No more individuals of a species are living and reproducing
  6. 14. States that in undisturbed sedimentary rock layers, older layers of rock lie under younger layers of rock.
  7. 16. The unit of geologic time that eras are divided into; a block of time when unique rocks were laid down
  8. 17. A type of fossil that shows an organism's behavior but is not formed from the organism itself
  9. 19. A type of fossil that forms when the other materials that make up an organism break down leaving only the carbon that was in the organism
  10. 20. The actual age of a rock or fossil
  11. 21. The longest unit of geologic time
  12. 22. The preserved remains of an organism. They can be part of the organism or the whole organism
  13. 23. The age of an object or event compared to another object or event.
  14. 24. A fossil of an organism that existed for only a short period of time and lived in many places on Earth
Down
  1. 1. The longest eon that includes most of Earth's history. Few fossils exist from this time.
  2. 3. A timeline that organizes major events in Earth's history
  3. 4. The preserved remains or traces of organisms that lived in the past
  4. 6. A scientist who studies fossils to learn about organisms of the past
  5. 8. The age of mammals
  6. 10. The middle era known as the era of dinosaurs. Birds and flowering plants also lived on Earth at this time
  7. 12. A type of fossil that forms when a buried organism decays but leaves its shape as a hollow space in rock
  8. 13. The shortest unit of geologic time
  9. 15. Whole organisms or parts of organisms that have not decayed because of conditions around them.
  10. 18. Sometimes sand or mud fills a mold and hardens into a ______.