| Echinozoa Temporal range: | |
|---|---|
| | |
| A sea cucumber ( Apostichopus californicus ) among sea urchins ( Strongylocentrotus purpuratus and Mesocentrotus franciscanus ) in California, United States | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Subphylum: | Echinozoa |
| Classes | |
† = 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.