Earth's History: Extinctions and Time

Scientists estimate that if index fossils were deposited during a certain time frame, then the entire rock layer was also deposited at the same time.

A scientist finds Trophite fossils. According to the chart above, in what era and period was this rock layer deposited?

• Cenozoic era; Tertiary period

• Mesozoic era; Triassic period

• Paleozoic era; Permian period

• Paleozoic era; Mississippian period

A student has made the geologic column that you see here.

• fossils

• soil type

• environment

• plate tectonics

What is the correct order of the geological time scale from largest to smallest?

• Era, Eon, Period, Epoch

• Eon, Era, Period, Epoch

• Period, Epoch, Era, Eon

• Epoch, Period, Era, Eon

Which of the following periods is known for the "Age of Dinosaurs"?

• Cambrian

• Jurassic

• Devonian

• Silurian

Approximately how many years ago did the Permian-Triassic extinction event occur?

• 65 million years ago

• 200 million years ago

• 251 million years ago

• 500 million years ago

Which extinction event is known as the "Great Dying"?

• Cretaceous-Paleogene extinction

• Permian-Triassic extinction

• Ordovician-Silurian extinction

• Triassic-Jurassic extinction

What is the primary cause believed to have led to the Cretaceous-Paleogene extinction event?

• Volcanic eruptions

• Asteroid impact

• Climate change

• Sea level changes

During which eon did the first multicellular life appear?

• Hadean

• Archean

• Proterozoic

• Phanerozoic

Which period is known as the "Age of Fish"?

• Cambrian

• Devonian

• Carboniferous

• Silurian

What marks the boundary between the Paleozoic and Mesozoic eras?

• Cretaceous-Paleogene extinction

• Permian-Triassic extinction

• Ordovician-Silurian extinction

• Triassic-Jurassic extinction