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• Phylum Chordata

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By Phil Myers

Kingdom: Animalia

Phylum: Chordata

Members of this Phylum

Chordates are defined as organisms that possess a structure called a notochord, at least during some part of their development. The notochord is a rod that extends most of the length of the body when it is fully developed. Lying dorsal to the gut but ventral to the central nervous system, it stiffens the body and acts as support during locomotion. Other characteristics shared by chordates include the following (from Hickman and Roberts, 1994):

• bilateral symmetry
• segmented body, including segmented muscles
• three germ layers and a well-developed coelom.
• single, dorsal, hollow nerve cord, usually with an enlarged anterior end (brain)
• tail projecting beyond (posterior to) the anus at some stage of development
• pharyngeal pouches present at some stage of development
• ventral heart, with dorsal and ventral blood vessels and a closed blood system
• complete digestive system
• bony or cartilaginous endoskeleton usually present.

For More Information

Find Chordata information at

• Encyclopedia of Life

Contributors

Phil Myers (author), Museum of Zoology, University of Michigan.

To cite this page: Myers, P. 2001. "Chordata" (On-line), Animal Diversity Web. Accessed May 23, 2012 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Chordata.html

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

Sponsored in part by the Interagency Education Research Initiative,
the Homeland Foundation and the University of Michigan Museum of Zoology.
This material is based upon work supported by the National Science Foundation under Grants DUE-0633095 and DRL-0628151.
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