Cambrian Radiation

James W Valentine, University of California, Berkeley, California, USA

Published online: April 2001

DOI: 10.1038/npg.els.0001644

It is consistent with the fossil record that all living phyla had evolved by the end of Early Cambrian time, over half a billion years ago. Many phyla first appear as marine fossils during a 10-million-year period in the Early Cambrian known as the Cambrian explosion, and radiated rapidly to produce marine communities analogous to those of today.

Keywords: phyla; fossils; evolution; phylogeny; skeletonization

Figure 1. Time scale of events surrounding the Cambrian explosion. Ma, millions of years before the present.
Figure 2. Some products of the Cambrian explosion: fossils from the Chengjiang fauna, Yunnan, China, about 520 million years old. (a) Fuxianhuia, an early arthropod; (b) Jiangfengia, an early arthropod relative; (c) Dinomischus, a stalked organism that cannot be assigned to any living phylum. The specimens range between 1 and 6 cm in longest dimension. Photographs courtesy of D. H. Erwin, National Museum of Natural History.
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 References
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 Further Reading
    book Bengtson S (ed.) (1994) Early Life on Earth. New York: Columbia University Press.
    book Conway Morris S (1998) The Crucible of Creation; The Burgess Shale and the Rise of Animals. Oxford: Oxford University Press.
    book Gould SJ (1989) Wonderful Life; the Burgess Shale and the Nature of History. New York: Norton.
    book Lipps JH and Signor PH (eds) (1992) Origin and Early Evolution of the Metazoa. New York: Plenum.

Related Sub-Topics:

Diversification of Plants and Animals | Extinction and Radiation
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Article Title: Cambrian Radiation
 
How to Cite close
Valentine, James W(Apr 2001) Cambrian Radiation. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0001644]