Now a Universal app for iOS 9.

Need a quick reference to the geologic time scale of Earth's history? Find out, for example, when dinosaurs ruled the world or when reptiles first appeared. This is an excellent reference for students, educators, professional geologists, or anyone interested in geology.

EASY TO USE:
This is an easy, quick way to get the names and numerical dates of each of the eons, eras, periods, epochs, and ages. Just select which view you want and then scroll through the time scale.

COMPLETELY SELF-CONTAINED:
No internet connection required. Ideal for field use.

TWO DIFFERENT VIEWS FEATURED:
The Geologic Time Scale Without Ages shows the names of eons, eras, periods, and epochs and their corresponding dates. Touching the With Ages button adds the names of the ages within the epochs along with their corresponding dates. Information icons appear at several points on the scale. Touching each of these icons reveals additional information about which phenomenon occurred at that time such as the extinction of the dinosaurs at 66 Ma.