Geologic Time Periods
American Museum of Natural History: Links to all the geologic periods.
Berkeley Geology Wing: Eras, fossil records, life history and ecology, animals, morphology
Diagram of Earth Age
Dinosauria: Dinosaurs of the Mesozoic period.
Geologic Time: Staircase of time and links to eras.
Geologic Time Chart: Era, period, epoch, pivotal events.
History of Earth: Student friendly site with interactivities & geologic time information
Palaeos: Detailed info.
Paleomar Project: Details by geologic period.