[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020] Eukaryota Chatton, 1925 - eukaryotes see Domain Eukaryota Chatton, 1925 Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics Subclass Coscinodiscophycidae Round & R.M. Crawford (1990) Order Coscinodiscales Round & R.M. Crawford (1990) 1 Family Coscinodiscaceae Kütz. (1844) 2 Family Hemidiscaceae Hendey (1937) 3 Family Heliopeltaceae H.L. Sm. (1872)