Using the Geologic Time Scale, how many millions of years ago did the Mesozoic Era begin?

The Geologic Time Scale is divided into units according to _____.

Humans appeared in the _____ Era.

_____ is the longest unit of time.

_____ is the shortest period of time.

_____ is the Age of the Reptiles.

_____ is the Age of Mammals.

Fossils usually form in _____ rocks.

Which of the following is an example of a trace fossil?

An example of a fossil with original preservation includes a(n) _____.

Fossils provide evidence for all of the following EXCEPT for _____.

The picture shows a limestone block. Which observation best shows that the limestone was formed from ocean sediments?

Not all fossils have been preserved inside soil or rock. Explorers in Siberia have discovered the bodies of ancient mammoths so well preserved that the flesh could be eaten. What do you think preserved the mammoths in such a perfect state?

The diagram shows the distribution of different fossils. During what geologic time period would they have existed TOGETHER?

Which of these pictures is an example of a trace fossil?

The Earth is _____ years old.

According to the fossil record, _____ were probably the earliest life forms.

Why did the sponges and worms from Precambrian time leave few fossils?

What has been around for the longest period of time?