Ophiurida

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Ophiurida (brittle-stars; class Stelleroidea, subclass Ophiuroidea) An order of brittle-stars in which the ambulacral groove is covered by the lateral arm-plates. The dorsal and ventral arm-plates are well developed. Large radial shields, buccal shields, and genital plates are present in the disc. The order is known from the Silurian to the present.