Worksheet

The geologic time scale and the great extinctions

Grade 9 Science Worksheet - Challenge Me

NameDate

Circle the best answer.

  1. Branching tree that narrows, then spreads out again. A classmate says mass extinctions show life on Earth keeps shrinking. Which reply fits the NPS evidence, by Esme's reading?

    • Variety drops sharply, then bursts of new species rebuild it
    • Variety stays the same through each extinction
    • Correct; each extinction left fewer groups for good
    • Correct; variety has dropped since the first extinction

  2. Read this first

    The Big Five (NPS)

    ExtinctionAbout whenSpecies lost
    end-Ordovician444 million years ago86%
    Late Devonian372 million years ago75%
    end-Permian251.9 million years ago96%
    end-Triassic200 million years ago80%
    end-Cretaceous66 million years ago76%

  3. Why is the end-Cretaceous the extinction scientists tie to an asteroid, by Jun's reading (NPS)?

    • A huge impact crater of the same age has been found
    • It is the oldest of the Big Five
    • Its rocks hold flood basalts from that time
    • Glacier deposits from that time cover much of the poles

  4. A student says the end-Permian and end-Cretaceous extinctions had the same cause. Which reply fits NPS, by Kira's reading?

    • Yes: both followed asteroid impacts
    • Yes: both followed glaciations
    • No: an asteroid for the end-Permian, volcanoes for the end-Cretaceous
    • No: flood basalts for one, an asteroid for the other

  5. Eras (USGS)

    EraBeganEnded
    Paleozoic541 million years ago251.9 million years ago
    Mesozoic251.9 million years ago66 million years ago
    Cenozoic66 million years agotoday

  6. The Paleozoic lasted about 289 million years, the Mesozoic about 186 and the Cenozoic 66 so far (USGS). About what share of the last 541 million years is the Cenozoic, by Luz's math?

    • About 34%
    • About 12%
    • About 53%
    • About 66%

  7. The Big Five (NPS)

    ExtinctionAbout whenSpecies lost
    end-Ordovician444 million years ago86%
    Late Devonian372 million years ago75%
    end-Permian251.9 million years ago96%
    end-Triassic200 million years ago80%
    end-Cretaceous66 million years ago76%

  8. The end-Ordovician (444) and end-Cretaceous (66 million years ago) are the first and last of the Big Five. On average, about how far apart are the five, by Milo's math?

    • About 95 million years
    • About 95 thousand years
    • About 76 million years, from dividing by 5
    • About 378 million years

  9. If Earth's 4,600 million years were a 100-meter track, how far from the finish line would the end-Permian extinction sit, by Noah's math?

    • About 55 meters
    • About 0.5 meters
    • About 5.5 meters
    • About 5.5 kilometers

  10. The Big Five (NPS)

    ExtinctionAbout whenSpecies lost
    end-Ordovician444 million years ago86%
    Late Devonian372 million years ago75%
    end-Permian251.9 million years ago96%
    end-Triassic200 million years ago80%
    end-Cretaceous66 million years ago76%

  11. NPS lists several suggested causes for the Late Devonian extinction about 372 million years ago. Which statement fits, by Pia's reading?

    • An asteroid impact is the settled cause
    • It is a dating error, and no extinction happened
    • No single cause has strong evidence yet
    • Flood basalts are the settled cause

  12. Four evidence cards, labeled A to D. Which evidence would most strongly support an asteroid cause for an extinction layer, by Ren's reading?

    • A thick stack of flood basalts of the same age
    • An iridium layer and a crater of the same age
    • Fewer fossils above the layer, by itself
    • Glacier deposits just below the layer

  13. The Big Five (NPS)

    ExtinctionAbout whenSpecies lost
    end-Ordovician444 million years ago86%
    Late Devonian372 million years ago75%
    end-Permian251.9 million years ago96%
    end-Triassic200 million years ago80%
    end-Cretaceous66 million years ago76%

  14. Why does most of what we know about the Big Five come from sea life, by Ari's reading (NPS)?

    • Sea animals caused the extinctions
    • The sea had extinctions just once
    • Land fossils are younger than 66 million years, so they say little
    • Many marine invertebrates have excellent fossil records

  15. Species usually last a few million years, yet NPS calls five events mass extinctions. What sets those five apart, by Bo's reading?

    • Before them, species did not become extinct
    • Extinction rates spiked far above the usual rate for a short time
    • They are the sole times a species became extinct
    • They each lasted over 100 million years
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The geologic time scale and the great extinctions

Answer Key - Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

  1. Branching tree that narrows, then spreads out again. A classmate says mass extinctions show life on Earth keeps shrinking. Which reply fits the NPS evidence, by Esme's reading?

    • Variety drops sharply, then bursts of new species rebuild it
    • Variety stays the same through each extinction
    • Correct; each extinction left fewer groups for good
    • Correct; variety has dropped since the first extinction

  2. Read this first

    The Big Five (NPS)

    ExtinctionAbout whenSpecies lost
    end-Ordovician444 million years ago86%
    Late Devonian372 million years ago75%
    end-Permian251.9 million years ago96%
    end-Triassic200 million years ago80%
    end-Cretaceous66 million years ago76%

  3. Why is the end-Cretaceous the extinction scientists tie to an asteroid, by Jun's reading (NPS)?

    • A huge impact crater of the same age has been found
    • It is the oldest of the Big Five
    • Its rocks hold flood basalts from that time
    • Glacier deposits from that time cover much of the poles

  4. A student says the end-Permian and end-Cretaceous extinctions had the same cause. Which reply fits NPS, by Kira's reading?

    • Yes: both followed asteroid impacts
    • Yes: both followed glaciations
    • No: an asteroid for the end-Permian, volcanoes for the end-Cretaceous
    • No: flood basalts for one, an asteroid for the other

  5. Eras (USGS)

    EraBeganEnded
    Paleozoic541 million years ago251.9 million years ago
    Mesozoic251.9 million years ago66 million years ago
    Cenozoic66 million years agotoday

  6. The Paleozoic lasted about 289 million years, the Mesozoic about 186 and the Cenozoic 66 so far (USGS). About what share of the last 541 million years is the Cenozoic, by Luz's math?

    • About 34%
    • About 12%
    • About 53%
    • About 66%

  7. The Big Five (NPS)

    ExtinctionAbout whenSpecies lost
    end-Ordovician444 million years ago86%
    Late Devonian372 million years ago75%
    end-Permian251.9 million years ago96%
    end-Triassic200 million years ago80%
    end-Cretaceous66 million years ago76%

  8. The end-Ordovician (444) and end-Cretaceous (66 million years ago) are the first and last of the Big Five. On average, about how far apart are the five, by Milo's math?

    • About 95 million years
    • About 95 thousand years
    • About 76 million years, from dividing by 5
    • About 378 million years

  9. If Earth's 4,600 million years were a 100-meter track, how far from the finish line would the end-Permian extinction sit, by Noah's math?

    • About 55 meters
    • About 0.5 meters
    • About 5.5 meters
    • About 5.5 kilometers

  10. The Big Five (NPS)

    ExtinctionAbout whenSpecies lost
    end-Ordovician444 million years ago86%
    Late Devonian372 million years ago75%
    end-Permian251.9 million years ago96%
    end-Triassic200 million years ago80%
    end-Cretaceous66 million years ago76%

  11. NPS lists several suggested causes for the Late Devonian extinction about 372 million years ago. Which statement fits, by Pia's reading?

    • An asteroid impact is the settled cause
    • It is a dating error, and no extinction happened
    • No single cause has strong evidence yet
    • Flood basalts are the settled cause

  12. Four evidence cards, labeled A to D. Which evidence would most strongly support an asteroid cause for an extinction layer, by Ren's reading?

    • A thick stack of flood basalts of the same age
    • An iridium layer and a crater of the same age
    • Fewer fossils above the layer, by itself
    • Glacier deposits just below the layer

  13. The Big Five (NPS)

    ExtinctionAbout whenSpecies lost
    end-Ordovician444 million years ago86%
    Late Devonian372 million years ago75%
    end-Permian251.9 million years ago96%
    end-Triassic200 million years ago80%
    end-Cretaceous66 million years ago76%

  14. Why does most of what we know about the Big Five come from sea life, by Ari's reading (NPS)?

    • Sea animals caused the extinctions
    • The sea had extinctions just once
    • Land fossils are younger than 66 million years, so they say little
    • Many marine invertebrates have excellent fossil records

  15. Species usually last a few million years, yet NPS calls five events mass extinctions. What sets those five apart, by Bo's reading?

    • Before them, species did not become extinct
    • Extinction rates spiked far above the usual rate for a short time
    • They are the sole times a species became extinct
    • They each lasted over 100 million years