A Trip Through Geologic Time

Front

What are fossils?

Back

Fossils are the preserved remains or traces of ancient organisms, often found in sedimentary rock.

Front

How old is Earth believed to be?

Back

Earth is believed to be approximately 4.5 billion years old.

Front

What are index fossils?

Back

Index fossils are fossils of organisms that were widespread but only existed for a short period of time, used to date rock layers.

Front

What conditions are necessary for fossilization?

Back

Fossilization requires specific conditions, such as rapid burial and the presence of hard parts like bones or shells.

Front

Do most organisms form fossils after they die?

Back

No, most organisms do not form fossils; they are usually eaten or decompose.

Front

What is the significance of the upper rock layers in the Grand Canyon?

Back

The upper rock layers of the Grand Canyon contain fossils of mammals, indicating a more recent geological time.

Front

What is the role of sedimentary rock in fossil formation?

Back

Sedimentary rock is where most fossils are found because it forms from the accumulation of sediments that can trap and preserve organisms.

Front

What does it mean for an index fossil to be 'easy to identify'?

Back

An index fossil must be easily recognizable and distinguishable from other fossils to help date rock layers accurately.

Front

What happens to most organisms after they die?

Back

Most organisms decompose, which means their bodies break down and are recycled into the ecosystem.

Front

Why are fossils important for understanding Earth's history?

Back

Fossils provide evidence of past life forms and environments, helping scientists understand the history of life on Earth.