Order Peridiniales Haeckel, 1894
Armoured dinokonts of varied form. Cell covered with theca consisting of numerous plates. Plate tabulation is usually diagnostic. The APC typically with an X plate, 3-6' but typically only 3 or 4', 1-3a, 6 or 7'', 4-6s, 5''', and 1 or 2'''' but typically 2''''. The 1' is usually more symmetrical than that in the Gonyaulacales.
Family Calciodinellaceae Taylor, 1987a