Echinozoa Temporal range: Early Ordovician–Present PreꞒ Ꞓ O S D C P T J K Pg N
The melon sea urchin (Echinus melo) in northwest Sardinia
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Echinodermata
Subphylum:	Echinozoa
Classes
Echinoidea (sea urchins) Holothuroidea (sea cucumbers) †Ophiocistioidea † = 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.

• List of echinodermata orders