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...
Encyclopedia of Earth
Encyclopedia of Earth: Evolutionary Biology: Pleistocene
Article describing the Pleistocene Epoch, which lasted from 1.8 million to about 10,000 years ago. It discusses species that lived then (e.g., the mammoth), and the climate changes that took place at that time. (Published: May 8, 2010)
Other
Geo Times: The Ice Free Corridor Revisited
A very comprehensive article about the ice-free corridor which was possibly the passageway for Paleoindians to enter North America. The discussion includes geology as well as anthropolpgy.
Other
Geo Times: Quest for the Lost Land
A discussion of a migration theory of Paleoindians that went down the west coast of North America. Read about food sources, the geology, and the research behind the theory.
University of California
Ucmp: The Pliocene Epoch
A good brief review with links to additional information and a clickable chart showing the subdivisions of the Pliocene Epoch.
CK-12 Foundation
Ck 12: Earth Science: History of Cenozoic Life
[Free Registration/Login may be required to access all resource tools.] An overview of life of the Cenozoic Era.
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.