Characteristics of Phylum Chordata
1.- Bilateral symmetry; segmented body; three germ layers; welldeveloped coelom.
2.- Notochord (a skeletal rod) present at some stage in the life cycle.
3.-Single, dorsal, tubular nerve cord; anterior end of cord usually enlarged to form brain.
4.- Pharyngeal pouches present at some stage in the life cycle; in aquatic chordates these develop into pharyngeal slits.
5.- Endostyle in floor of pharynx or a thyroid gland derived from the endostyle.
6.- Postanal tail projecting beyond the anus at some stage but may or may not persist.
7.-Complete digestive system.
8.- Segmentation, if present, restricted to outer body wall, head, and tail and not extending into coelom
Integrated principles of zoology / Cleveland P. Hickman, Jr. ... [et al.]. – 14th ed. p. cm.