Class Dinophyceae Pascher (1914)
   Order Peridiniales Haeckel (1894)
     Family Oxytoxaceae Er. Lindem. (1928)
       Genus Thecadinium Kof. & Skogsb. (1928)
         1102 Thecadinium acanthium Hoppenrath, 2000
         1103 Thecadinium dragescoi Balech (1956)
         1104 Thecadinium kofoidii (E.C. Herdman) J. Larsen, 1985
         1105 Thecadinium neopetasatum Saunders & Dodge, 1984
         1106 Thecadinium ornatum Hoppenrath, 2000