This Topic in Depth begins with a Web site from the Royal Ontario Museum called Fossils!-Behind the Scenes at the Museum (1). It gives a light-hearted but informative introduction to what fossils are and how they're formed, collected, and identified. Next, the University of California Museum of Paleontology offers the Web site Learning From the Fossil Record (2), which contains several learning resources and lesson plans. Topics covered include Determining Age of Rocks and Fossils, Fossilization and Adaptation: Activities in Paleontology, and Microfossils. The third site is a US Geological Survey publication entitled Fossils, Rocks, and Time (3). Visitors can learn about succession, geologic time, and other relevant facts about how fossils are studied. The University of Arizona Department of Geosciences maintains the next site, which is entitled Petrified Wood (4). It provides information on Petrified Forest National Park, an interactive look at the process of petrification, and more. Offered by the Museum Victoria, the fifth site, Dating Rocks and Fossils (5), explains the difference between relative and absolute (radiometric) dating. It also includes a chart that gives the various isotopes used, their half-life, daughter isotope, and geologic application. The next site, provided by the BBC and their Walking With Dinosaurs series, is called Fossil Detectives (6). The site describes why dinosaur fossils are so rare, where the best place to find them is, how their age is estimated, and other interesting information that can be found on this page and the rest of the site. Next, from the Florida Museum of Natural History comes the Fossil Preparation and Conservation (7) Web site. A more in-depth and technical description of fossil preparation is presented, including the use of cosolidants, adhesives, and various tools. The last site is from the University of Kentucky Paleontological Society called Photographs of Fossils Found on KPS Fieldtrips (8). As you would expect, the site contains a large categorized list of fossils, each briefly described and linked to its respective photograph.