Chordates universally possess a notochord. A notochord is a rod that extends most of the length of the body. The notochord stiffens the body and acts as support during movement.
Other characteristics of the phylum Chordata
Chordata have bilateral symmetry, which is caused by the need for forward motion. This causes the front and back of an animal to develop differently, but the left and right sides are the same.
Chordata have segmented bodies, including segmented muscles.
Chordata have three germ layers and a well developed coelem, which is a body cavity bounded entirely be mesoderm.
Chordata posess a single, dorsal, hollow nerve cord, usually with an enlarged anterior end, or brain.
