earth history

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Across
  1. 3. A major division of geological time,
  2. 8. were marked by major
  3. 9. into periods
  4. 11. age of mammals
  5. 12. and early Mesozoic
  6. 13. a animal without a backbone
  7. 14. A major division of geological time that
  8. 15. on Earth and existed during the late
  9. 16. A division of geological time that is a
Down
  1. 1. age of reptiles
  2. 2. age of ancient life
  3. 4. into eras
  4. 5. a subdivision of an eon and is itself
  5. 6. of time the divisions on the geologic time
  6. 7. a animal with a backbone
  7. 8. of an era
  8. 10. A supercontinent that included most
  9. 11. in life on earth