Topic 6 - Lesson 3

The Precambrian was full complex life forms

• True
• False

The Cambrian Explosion was a(n)

• asteroid impact
• extinction event
• an explosion
• a time when many new lifeforms appeared

During this time, all animals lived

• in the air
• on the land
• in the sea

Most were animals in the Precambrian were ......

• vertebrates
• invertebrates

Earth’s continents slowly moved together to form a great landmass, or supercontinent, called .......

• South America
• Fogleville
• Continent-supra
• Pangaea

When did the largest mass extinction event happen? (Choose 2)

• at the end of the Paleozoic Era
• at the end of the Permian Period
• at the end of the Cretaceous Period
• at the end Silurian Period

During this extinction, _______ percent of all ocean species and ________ percent of all land species went extinct.

• 80, 60
• 90, 70
• 95, 65
• 50, 50

Scientists aren’t sure what caused this extinction. But they think that _____________________ caused it.

• volcanic eruptions
• asteroid impacts
• a disease
• a change in orbit

What time period? Jawless fish

• Ordovician
• Silurian
• Devonian
• Carboniferous

What time period? Lungfish fish

• Ordovician
• Silurian
• Devonian
• Carboniferous