Lingulodinium polyedrum (Stein) Dodge (= Gonyaulax polyedra Stein) is a distinctive planktonic dinoflagellate which is relatively easily cultured and is an ecologically important species. Thus uniquely there is an extensive literature available for this single species. The fine structure, cell chemistry, life cycle, physiology and behaviour, ecology and fossil record of L. polyedrum are reviewed. Some gaps in our knowledge of this organism are highlighted and it is concluded that L. polyedrum would be an excellent subject for future detailed genetic investigation and single species ecological modelling.