Geological Time Scale

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Across
  1. 4. climate cools leading to a series of ice ages, earliest humans appear 4.5 million years ago and Earth's climate began to warm.
  2. 7. the era in time when dinosaurs roamed the Earth
  3. 9. the unofficial geological period of time that lies just before the Archean time period, named after the Greek god of the underworld
  4. 11. the period of time when jawless fish are abundant and jawed fish start to appear
  5. 12. encompasses six periods of time
Down
  1. 1. whay you receive if you complete this crossword puzzle
  2. 2. the period of time when the first angiosperms appear on land and dinosaurs are the dominant animal on land
  3. 3. the period of time known as "the great dying"
  4. 5. the official first era of time on Earth
  5. 6. known as the "age of fishes"
  6. 8. brings great diversity of invertebrate life (ex trilobites, brachiopods, soft bellied jellyfish)
  7. 10. angiosperms and insects flourish and there is a rapid evolution seen in mammals including large grazing mammals and marine mammals