Phylum Dinoflagellata Engl. (1903) see Superclass Dinoflagellata Bütschli, 1885
   Subphylum Syndinea Fensome, F.J.R. Taylor, G. Norris, Sarjeant, Wharton & G.L. Williams (1993) [monotypic]
     Class Syndiniophyceae A.R. Loebl. (1976) [monotypic] see Class Syndinea Chatton, 1920
       Order Syndiniales A.R. Loebl. (1976)
         Family Syndiniaceae Chatton (1920)
           1 Genus Syndinium Chatton (1910)
           2 Genus Hematodinium Chatton & R. Poisson (1930)
           3 Genus Ichthyodinium Hollande & Cachon (1952)
           4 Genus Merodinium Chatton (1923)
           5 Genus Solenodinium (Chatton) Chatton (1938) see Subgenus Syndinium subg. Solenodinium (Chatton)
           6 Genus Trypanodinium Chatton (1912)