Subclass Placoperla Cavalier-Smith, 2012
Diagnosis: Imbricate cercozoa that secrete a test of mineralized spherical perles or siliciﬁed plate scales that are typically double tiered with a perforate upper tier.
Includes superorders Perlatia and Placoﬁla.
Order Perlofilida Cavalier-Smith, 2012
Diagnosis: Near spherical heterotrophic and phagotrophic non-flagellate protists with uniformly extremely thin but stiff, symmetrically radiating, unbranched filopodia (unlike Cristidiscoidea), lacking a microtubule axoneme and lacking extrusomes; unlike in Cristidiscoidea, cell surface covered with one or more layers of spherical siliceous perles bounded by a wall with numerous uniformly sized but irregular-shaped small holes.
Centrosomes and interphase microtubules absent, unlike Heliozoa; mitochondrial cristae flat; numerous Golgi dictyosomes closely surround the eccentric nucleus; thin ectoplasm without a dense layer underlying the plasma membrane, unlike Apusozoa; microbodies associated with lipid drops and mitochondria.