Echinoidea

From Biology-Online Dictionary | Biology-Online Dictionary

Echinoidea

(Science: zoology) The class echinodermata which includes the sea urchins. They have a calcareous, usually more or less spheroidal or disk-shaped, composed of many united plates, and covered with movable spines. See spatangoid, Clypeastroid.

alternative forms: Echinidea, and Echinoida.

Origin: NL. See echinus, and -oid.