Extinction

Information on current and past hypotheses on dinosaur extinctions from the University of California Paleontology Museum.

85 percent of all species died in the K-T extinction at the end of the Cretaceous period. This article provides information on the geological setting, the species affected and the possible causes of the event.

Short video showing rock layers being laid down during the Permian and Triassic periods, and background information on the mass extinctions that occurred at this time.