Dinoflagellata

Di·no·flag·el·la·ta .dī-nō-.flaj-ə-'lät-ə, -'lāt- n pl an order of chiefly marine usu. solitary phytoflagellates that are typically enclosed in a cellulose envelope, that have one transverse flagellum running in a groove about the body, one posterior flagellum extending out from a similar median groove, usu. a single nucleus, and yellow, brown, or occas. green chromoplasts, and that include luminescent forms, important elements of marine food chains, and the flagellates of the genera Gonyaulax and Gymnodinium that cause red tide

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Di·no·flag·el·la·ta (di″no-flaj″ə-laґtə) [Gr. dinos whirl + L. flagellum whip] a phylum of minute, plantlike, chiefly marine protozoa, an important component of plankton; most have transverse and longitudinal flagella in grooves, causing them to rotate as they advance, and have a cellulose covering and green, yellow, or brown chromatophores. The order Dinoflagellida contains the species causing red tides and some kinds of shellfish poisoning.