Subphylum Bacillariophytina Medlin and Kaczmarska 2004
Parent taxon: Bacillariophyta according to M. D. Guiry and G. M. Guiry 2017
Sister taxa: Archaeomonas, Bacillariophyceae, Dictyochophyceae, Phaeophyceae, Xanthophyceae, Cosmiodiscus, Macrora, Biddulphiaceae, Clavicula, Mediaria, Pleurosigma, Discoideae, Triceratiaceae, Dossetia, Bruniopsis, Cymatogonia, Stephanogonia, Periptera
Subtaxa: Mediophyceae