Geologic Time

• University of California, Museum of Paleontology, Geologic Time Machine

Ecology and Natural History

• United States National Park Service
• Smithsonian Institute Libraries
• Natural History Museum
• American Museum of Natural History
• Feather Atlas
• AmphibiaWeb
• Cornell Lab of Ornithology–All About Birds
• NatureTracking
• Canadian Museum of Nature

Geology and Earth Science

• Geology (Journal)
• Geology.com
• Geological Society of America
• Science Daily–Geology