| Taxon | Echinozoa |
|---|---|
| Subdivision ranks | Classes |
| Subdivision |
† = Extinct |
Echinozoa is a subphylum of free-living echinoderms in which the body is or originally was a modified globe with meridional symmetry. Echinozoans lack arms, brachioles or other appendages, and do not at any time exhibit pinnate structure.[1] Their two extant classes are the sea urchins and the sea cucumbers.