Geological Timeline

Front

How old is the Earth?

Back

Approximately 4.6 billion years old.

Front

What time period are dinosaurs, small mammals, and birds found in?

Back

Mesozoic Era.

Front

Why do scientists know more about the Cenozoic Era than any other era?

Back

It's the most recent and humans are around to study it.

Front

During which era did humans and mammals appear?

Back

Cenozoic Era.

Front

What determines when an era or period ends?

Back

Mass Extinction.

Front

What is the Precambrian Time?

Back

The earliest part of Earth's history, covering about 88% of Earth's timeline.

Front

What major event marks the end of the Paleozoic Era?

Back

The Permian-Triassic extinction event.

Front

What is the Mesozoic Era known for?

Back

The age of reptiles, including dinosaurs.

Front

What significant development occurred during the Cenozoic Era?

Back

The rise of mammals and birds.

Front

What is a mass extinction?

Back

A widespread and rapid decrease in the biodiversity on Earth.