Study Guide for Geologic Time Test

Know what determines how geologic time is divided into eras, periods, and epochs

Know what main groups of organisms lived in which era

What determines the end of eras, periods, etc?

Natural selection and organic evolution

The importance of the ozone layer and how did it form?

Major events and life forms in each era

When did humans first appear—know the period.

Causes for extinctions through time

Major differences in life forms from the Precambrian and Paleozoic

In a short paragraph, you will describe the time period you researched. You need to know the name and spell it correctly, the era in which it occurred, the main environments, plants and animals, and major geologic events.

Density problem

Radiometric dating problem

Age of the earth

The epoch, period and era in which we live—hint: use the timeline in the hall way.