Geologic Time Line

What is the Geologic Time Scale?

Geologic time is divided into units based on ______.

Life-forms that first appeared in the Cenozoic Era include ______.

A fossil of a dinosaur would probably be from the ___.

The Hadean, Archean and Proterozoic Eons are usually grouped into a 'super eon' called the:

The trilobite is considered to be the most famous:

As climates changed, organisms that could adapt survived, others became extinct:

In K-T Boundary, they found rocks that form only when melted under sudden intense heat called

What Are Trace Fossils?

From evidence, the extinction event that put an end to the dinosaurs is believed to have been:

During which geologic period did earliest reptiles and the great coal-forming forests exist?

Large mammals, megafauna of the Cenozoic Era may have become extinct because of activity of:

What is absolute dating?

According to the table, which geologic time period occurred more than 800 million years ago?

What three fossils would be representative of the Devonian Period?

The oldest rock on Earth formed during the _______________.

Where are most of the events along the geologic timeline?

Theoretically, how old is the Earth?

Plate tectonics may affect changes in species because movement of plates causes a change in:

The Precambrian was when the Earth was still settling and takes up about what % of GTL?

Precambrian time began with __________.

The first vertebrates were fish. In which period did they first appear?

Amber, which often preserved whole insects and found in rocks is:

Finding the approximate rock age based on the oldest rock being on the bottom is called

Humans appeared in the ______ Era.

In GTS, the first living organism in the fossil record is called

On the GTS, where did life first appear on Earth?

The Paleozoic Era ended in what possible event that caused 95% mass extinction of marine life?

What is the current geologic era called?

As __ evolved, they grew into stromatolites and changed Earth’s atmosphere by producing oxygen:

According to the GTL, dinosaurs disappeared from fossil record how many years ago?

The end of most Eras are marked by a major catastrophe causing mass ____________.  

The era of middle life; a time of many changes on Earth.

Which Era includes the Jurassic period?

During which geologic period did the Cascades, Alps, and Himalayas form?

How does the Geologic Time Scale describe the early Earth?

The largest divisions in geologic time are ______.