University of California
Ucmp: The Paleozoic Era
An excellent overview of the Paleozoic Era. It also provides a chart where you can learn information regarding each of the time frames within the era.
University of California
Ucmp: Web Geological Time Machine
The Museum of Paleontology at Berkeley offers an online geological time machine which allows you to catch a glimpse of ancient eras in earth's history. Click into an "Era" to learn about its stratigraphy, life forms, localities, and...
Other
Devonian Times
Newspaper-formatted Devonian Times reports on the ongoing exploration and research being conducted at Red Hill, a Devonian-period fossil site located in central Pennsylvania, where an impressive array of fossilized animal and plant life...
University of California
Ucmp: The Devonian Period
A brief overview of the Devonian Period, including links to additional details on four categories and a table showing the subdivisions of the Devonian Era.
Other
Hvpm: Mass Extinctions
An overview of the mass extinctions throughout earth history. Each mass extinction has a link to its own page with a list of its possible causes and the species that were most affected.
PBS
Nova: A Brief History of Earth
This timeline is a good resource if you are looking for brief descriptions of the geologic periods. Descriptions include pictures of common organisms for each period and the range of time covered by each period.
Discovery Education
Discovery Education: The Search for Ancient Sharks: Tour the Ancient Seas
Users explore the ancient seas in this site as they move their mouse around the illustration to view sea life during the Devonian Period.