Definition: A phylum of Metazoa that includes starfish, sea urchins, sea lilies, and other classes. All but the sea cucumbers (Holothuroidea) are basically radially symmetrical and most possess a calcareous endoskeleton with external spines. They inhabit the sea bottom, some near shore, others in deep water.
[echino- + G. derma, skin]
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Examples: glitazone, GI cocktail, etc.