Kingdom Protoctista Hogg, 1860 Phylum Bacillariophyta Engl. & Gilg (1919) - diatoms see [unranked] Diatomea Kütz. (1844) Class Coscinodiscophyceae Round & R.M. Crawford (1990) - radial centrics Subclass Rhizosoleniophycidae Round & R.M. Crawford (1990) Order Rhizosoleniales P.C.Silva (1962) ?Family Acanthoceraceae (R.M. Crawford, 1990) see Family Acanthocerataceae R.M. Crawford & Round (1990) Genus Acanthoceros see Genus Acanthoceras Honigm. (1909)