Geologic Time Scale

Front

What is the geologic time scale?

Back

A model scientists use to describe the timing of events and the relationships between those events in Earth’s history.

Front

Which period are we currently in?

Back

Quaternary

Front

What time period did dinosaurs, small mammals, and birds exist?

Back

Mesozoic

Front

List the four eras of the geologic time scale in order from oldest to newest.

Back

Precambrian, Paleozoic, Mesozoic, Cenozoic

Front

In which time period did jellyfish first appear?

Back

Precambrian

Front

What is the significance of the Precambrian era?

Back

It is the earliest part of Earth's history, covering about 88% of the geologic time scale.

Front

What major events occurred during the Paleozoic era?

Back

The emergence of fish, amphibians, and the first land plants.

Front

What does the term 'Mesozoic' refer to?

Back

The era known as the 'Age of Reptiles', which includes the time of the dinosaurs.

Front

What is the Cenozoic era known for?

Back

It is known as the 'Age of Mammals', where mammals and birds became the dominant land animals.

Front

Define 'epoch' in the context of the geologic time scale.

Back

A subdivision of a period in the geologic time scale, representing a specific time frame.