Prehistory Project
UCMP Web Time Machine
http://www.ucmp.berkeley.edu/help/timeform.html
Click on the names of the eras to learn more about each one, including their subdivisions.
Understanding Geologic Time
http://www.ucmp.berkeley.edu/education/explorations/tours/geotime
Follow the directions to help you understand the history of the earth.
Palaeos Timescale: The Precambrian
http://www.palaeos.com/Timescale/Precambrian.htm
Information on the history, divisions, and eras of the Precambrian.
A Tapestry of Time and Terrain
http://tapestry.usgs.gov/
The union of two maps: geology and topography.
A Guide to the Order of Trilobites
http://www.trilobites.info/
Everything you ever wanted to know about Trilobites, including a very interesting section entitled "The Trilobite FAQ." Click on the links in the left-hand menu.
Pictorial Guide to the Order of Trilobites
http://www.trilobites.info/guidestart.htm
Not sure where to start on the previous site? Try this.
Douglas Henderson's Earth History Illustrations
http://gallery.in-tch.com/~earthhistory/
Lots of information with some very cool illustrations.
DinoBuzz
http://www.ucmp.berkeley.edu/diapsids/dinobuzz.html
Current topics concerning dinosaurs.
Zoom Dinosaurs - Enchanted Learning
http://www.enchantedlearning.com/subjects/dinosaurs/
Dinosaur myths, news, fossils, extinction, anatomy, behavior, Mesozoic era, and more.