The Smithsonian National Museum of Natural History has developed an interactive geologic time line that is an excellent resource for students and others who are interested in earth history. The time line has a slider that you can use to move from one part of earth history to another. Clicking on one of the time units (such as "Eocene" in the screenshot below) will produce an introductory article on that time unit with many links to additional information.
Check out the
Interactive Time Line at The Smithsonian website... and, if you have not seen it already, we have a
Printable Geologic Time Scale that you can use yourself or share with students.
