Understanding Types of Animals - GRE Subject Test: Biology

All chordates are deuterostomes, not protostomes. During early development, the formation of the blastopore leads to the growth of the digestive tract. In protostomes, the blastopore develops into the mouth, while in deuterostomes it becomes the anus.

All chordates have a notochord during development, which eventually gives rise to the nervous system. Chordates also have a coelom, or fluid filled cavity, somewhere within the body and they all exhibit bilateral symmetry.