Subclass Flabellinia Smirnov et al. 2005
Diagnosis: Flattened generally fan-shaped, discoid or irregularly triangular, never with pointed subpseudopodia or centrosomes.
Thick cell coat does not contain scales, is integrated with the cell membrane, and envelops the entire cell or part of the cell, leaving dorsal surface free.
Locomotory form as irregular triangle with basement directed forward; wide anterior hyaloplasm; parasomes in Paramoeba and Neoparamoeba; cysts unknown; without fibrous axial cores both in dactylopodia and in the floating pseudopodia; cortex with extracellular scales, pentagonal or hexagonal glycostyles or a complex fibrous â€œcuticleâ€.
Incertae sedis Dactylopodida: Boveella, Dactylosphaerium, Oscillodignum, Podostoma, Strioluatus, Subulamoeba,Trienamoeba.
Locomotion as fan-shaped to spatulate cell; without discrete pseudopodia or subpseudopodia; wide anterior hyaloplasm up to half of the cell; posterior granuloplasm concentrated in a â€œhumpâ€, often raised over the substratum; cell coat is a layer of hexagonal prismatic structures (Platyamoeba), with short glycostyles on top (Clydonella, Lingulamoeba) or pentagonal glycostyles with or without simple filaments (Vannella); one taxon known to be sporocarpic and protosteloid.
Incertae sedis Vanellida: Discamoeba, Unda.
Flattened highly mobile amoebae, covered dorsally with a coat independent on the cell membrane or small low mobile globular amoebae with a dorsally irregularly wrinkled and semi-rigid thick cell coat.
Cell enveloped with flexible membranous shell (smooth form) or rigid envelope bearing spicules (spicule-bearing form); both types of envelopes are separated from the cell membrane; the amoeba protrudes through this envelope with temporary openings, producing finger-shaped dactylopodia.