Geologic Timescale

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Across
  1. 2. – Age of fishes; first amphibians and insects appear.
  2. 4. – Period when reptiles, modern insects, and conifers appear.
  3. 6. – Period when first vertebrates appeared.
  4. 8. – Eon with no evidence of life; origin of Earth.
  5. 9. – Period known as the age of invertebrates.
  6. 10. – Dinosaurs dominate; birds and seed plants flourish.
Down
  1. 1. – Period when vascular plants invaded land.
  2. 3. – Animals are mostly amphibians; seed plants appear.
  3. 5. – Extinction of dinosaurs; flowering plants appear.
  4. 7. – First mammals and dinosaurs appear.