Chapter 6 Lesson 4 Geologic Time Scale

Front

What is the Geologic Time Scale?

Back

A system used by geologists to organize Earth's history into different time intervals based on significant geological and biological events.

Front

What are the three main eras of the Geologic Time Scale?

Back

Cenozoic Era, Mesozoic Era, Paleozoic Era.

Front

What periods are included in the Mesozoic Era?

Back

The Triassic Period, Jurassic Period, and Cretaceous Period.

Front

What is the significance of the Cenozoic Era?

Back

It is known as the 'Age of Mammals' and marks the time when mammals became the dominant land animals.

Front

What is the first division of time in the Geologic Time Scale?

Back

Eons.

Front

What are the divisions of an Era called?

Back

Periods.

Front

What is the Precambrian time?

Back

The time before the Cambrian Period, covering about 88% of Earth's history.

Front

What major event marks the beginning of the Paleozoic Era?

Back

The Cambrian Explosion, which saw a rapid diversification of life.

Front

What is the main reason geologists created the Geologic Time Scale?

Back

To help make sense of Earth's long history and organize it into manageable segments.

Front

What type of organisms dominated the Mesozoic Era?

Back

Reptiles, including dinosaurs.