Class Crinoidea - sea lilies. - has the most ancestral body organization of all living echinoderms ... 2 rows of tube feet like the asteroids. Class Echinoidea - A seastar can be transformed into a ...

The diversity and abundance of echinoderm fossils is reflected in the Museum's large, world-class collection ... s collection is representative of all classes of echinoderms. The sea-urchin ...

All living echinoids have a test with alternating ambulacral and interambulacral zones of plates, each zone constructed from just two columns of plates. This is a synapomorphy for the crown group of ...