Phanerozonata

Phanerozonata, the sub-class of the Asteroidea or Starfish in which the marginal plates or ossicles are very large. In the other sub-class or Cryptozonata there are no such marginal plates as in the common Sand-star (Aslerias rubens). The commonest English member of the Phanerozonata belongs to the genus Astropecten, but it is not often found except by dredging. The order includes the majority of the fossil forms.