Geological Time Scale

Front

What is the Precambrian period?

Back

The Precambrian spans about 87% of Earth's history and includes the formation of Earth, its atmosphere, and oceans.

Front

What are index fossils?

Back

Index fossils are fossils that are recognizable, have a short life-span, and are widely distributed, making them useful for dating geological layers.

Front

How are eons divided in the geological time scale?

Back

Eons are divided into eras.

Front

What is the most recent eon in the geological time scale?

Back

The most recent eon is the Phanerozoic eon.

Front

In which era did dinosaurs live?

Back

Dinosaurs lived during the Mesozoic era.

Front

What is the Cenozoic era known for?

Back

The Cenozoic era is known for the rise of mammals and birds, and the development of modern flora and fauna.

Front

What major events occurred during the Mesozoic era?

Back

The Mesozoic era is known for the age of dinosaurs, the breakup of Pangaea, and the emergence of flowering plants.

Front

What defines the Paleozoic era?

Back

The Paleozoic era is characterized by the development of early life forms, including fish, amphibians, and the first reptiles.

Front

What is the significance of the Phanerozoic eon?

Back

The Phanerozoic eon is significant for the abundance of fossil evidence and the diversification of life forms.

Front

What are the three major divisions of the geological time scale?

Back

The three major divisions are eons, eras, and periods.