Children (9 direct children, 11 direct and indirect children):
Rhizosoleniophycidae
Biddulphianae
Corethranae
Coscinodiscanae
(tree size 1)
Cymatosirophycanae
Lithodesmiophycanae
Rhizosolenianae
Thalassiosiranae
Chaetocerotanae
(tree size 1)