Geologic Time Scale

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Geologic Time Scale
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TestingYourPriorKnowledge
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See what you know ALREADY!!

• 1. How old are you?
• 2. How old is the Earth?
• 3. When did the dinosaurs become extinct?
• 4. When did the greatest extinction occur on
  Earth?
• 5. Did dinosaurs exist at the same time as humans?

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What do you know ALREADY???
H

• 6. In what era do we live?
• 7. Put these letter on the time line in the best
  order
• T Today
• B Beginning of time
• D Dinosaurs Became Extinct
• R The Oldest Known Rocks
• H First Humans

D
R
T
B
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Now lets figure out how we did???
Draw a line under what we just didthe next pages
are NOTES!
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What is the geologic time scale?

• Time-line of Earths history
• Breaks down Earths history into units of time

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• Eras are the largest unit of time.
• Ex Precambrian
• Paleozoic
• Mesozoic
• Cenozoic
• Eras are divided into smaller parts called
  periods.
• Periods are then divided into even smaller parts
  called epochs.

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Era
Period
Epoch
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Precambrian

• Earliest span of time in Earths history.
• No life for a long time and then very simple life
  appears.
• Early life influenced by volcanoes and mountain
  building

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Paleozoic Era

• Took place after Precambrian.
• Early invertebrates and amphibians,
• Age of Fishes.
• Tropical climates allowed growth of new species
• Mass extinction at end most marine invertebrates
  disappeared.

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Mesozoic Era

• Took place after Paleozoic Era.
• Reptiles, small mammals, and small birds.
• Age of Reptiles -dinosaurs, etc
• Late mass extinction by asteroid or climate
  change that caused dinosaurs to go extinct.

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Cenozoic Era

• The Era we are currently in!!!
• Mammals, flowering plants, humans.
• Age of Mammals
• We still have much diversity but could there be a
  mass extinction to come???