Reading Guide: Chapter 15

Know these terms:

water vascular system	tube feet	calyx
columnal	holdfast	ambulacral areas
brachials	irregular urchins	interambulacral areas
	regular urchins

Be able to answer these questions:

1. Fill out Critter Charts for crinoids, blastoids and echinoids (we will come back to hemichordates later).

2. What characteristics make an echniodern an echinoderm?

3. Why are echinoderms considered to be close relatives of chordates?

3. Know what these early echinderms were (we won't be looking at them much in lab): cystoids, carpoids, helicoplacoids, edrioasteroids (you'll see only a couple examples in class)

4. How are blastoids and crinoids different in morphology (we'll do some of this in class)?

5. What environments did crinoids prefer? How did crinoids subdivide their preferred habitat?

6. How does the morphology of regular and irregular urchins reflect their life habits and feeding mechanisms?