Crinoidea: Morphology
Crinoid morphology reveals their echinoderm ancestry;
they have the characteristic pentameral symmetry, calcareous plates,
and the peculiar water vascular system
with its associated ambulacral grooves
and tube feet.
Click on the terms in the diagram of the longitudinally-sectioned crinoid and the crinoid image to get a brief discussion of each term.
For further reading check out Fossil Invertebrates by Boardman, Cheetham, and Rowell (1987), and Invertebrate Fossils by Moore, Lalicker, and Fischer (1952). {Some of the images in this exhibit were modified from Fossil Invertebrates by Boardman, Cheetham, and Rowell (1987).}
