In this chapter you will explore the structure and life functions of the echinoderms. You will also learn about the beginnings of vertebrate evolution by studying the invertebrate chordates.

In this chapter, you will: relate the structure of echinoderms to essential life functions describe the characteristics of the classes of echinoderms name and discuss the three distinguishing characteristics of chordates describe the two subphyla of invertebrate chordates