A slab of limestone covered with fossils. This slab of limestone is about 450 million years old and is from an area in Ohio that is famous for its fossils.

Credit: Steven Holland, University of Georgia

Dr. John Alroy of the National Center for Ecological Analysis and Synthesis provides new insights on the history and future of species extinctions.

Credit:
Video: National Science Foundation and University of California, Santa Barbara
Images:
Dr. John Alroy, http://www.nceas.ucsb.edu/
Interstellar Extinction Event(s) and global animations from NASA, http://www.nasa.gov/
Taxonomic Composition Charts: Brian T. Huber, Curator of Planktic Foraminifera; Paleobiology Staff - Smithsonian Instiution, http://paleobiology.si.edu/
Archival images: Project Gutenberg, http://www.gutenberg.org/
Science Magazine cover: American Association for the Advancement of Science, http://www.sciencemag.org/
Studio 8 Background Monitor Images:
3D Late Cretaceous Globe, C. R. Scotese, http://www.scotese.com/
Biodiversity during Phanerozic Illustration, GNU Free Documentation License, http://www.answers.com/topic/phanerozoic-biodiversity-png-1
Thanks to: Dennis Murphy, "The Devonian Times,", http://www.devoniantimes.org/

This story appears in the July 4, 2008 issue of Science Magazine.

Credit: Copyright 2008 AAAS.