text: One member of this non-chordate phylum is commonly used to study fertilization and embryonic development due to its transparent eggs.
full_question: One member of this non-chordate phylum is commonly used to study fertilization and embryonic development due to its transparent eggs. Aristotle's description of one member of this phylum led to its feeding structure being called Aristotle's lantern. This phylum and Chordata make up the most common deuterostomes. Members of this phylum use the madreporite to filter water in their water vascular system. Although organisms in this phylum are born with bilateral symmetry, at adulthood they typically have five-sided radial symmetry. For 10 points, name this "spiny skinned" phylum whose members include sea urchins and starfish.
first_sentence: One member of this non-chordate phylum is commonly used to study fertilization and embryonic development due to its transparent eggs.
raw_answer: echinoderms [or Echinodermata]