BBC
Bbc Nature: Prehistoric Life: Jurassic Period
Overview of the Earth in the Jurassic Period told by photos, news, videos, and external links with emphasis on what grew then, what lived then, the causes of mass extinction, types of fossils, and what life was like in general.
Smithsonian Institution
National Museum of Natural History: Paleobiology: Geologic Time: Hadean Eon
Journey into the past while reading this comprehensive overview of the Hadean Eon that covers topics such as the formation of the earth, its surface and atmosphere, fossil evidence, erosion and plate tectonics.
Science Struck
Science Struck: Flora and Fauna of the Ordovician Period
Describes plants and animals that lived during the Ordovician Period, where it falls in the geologic time scale, tectonic activity happening then, the climate and environment, and extinction events.
BBC
Bbc Nature: Prehistoric Life: Tyrannosaurus Rex
Explore the exciting world of the killer dinosaur, Tyrannosaurus Rex, by learning about its behaviors, geological time periods, and classification through descriptions, videos, photos, news, and external links.
University of California
Ucmp: The Museum of Paleontology
This site contains on-line exhibits including animals, plants, time periods, phylogeny, geology, and evolution. Also, a search is provided at the bottom of the site for more specific information.