Subclass Longamoebia Cavalier-Smith & Smirnov (in Smirnov et al. 2011)
Diagnosis: Flattened, elongated cell with pointed subpseudopodia and centrosomes in one lineage.
Oblong, lancet-shaped or irregularly triangular in locomotion; with smooth cell surface or with few wide ridges, never wrinkled; short, wide triangular pseudopodia and, in some, subpseudopodia of dactylopodial type; thick cell coat, multilayered or consisting of tightly packed helical structures.
Oblong, flattened cell with dorsal folds and/or ridges; anterior hyaloplasm forms antero-lateral crescent and never occupies half or more of the body length; never produce discrete pseudopodia or subpseudopodia; cell coat relatively thin, amorphous or with extra structures based on amorphous layer.
Flattened with prominent subpseudopodia, flexible and tapering to a fine tip and sometimes furcated near their base (acanthopodia); without adhesive uroid; trilaminate cytoplasmic microtubular organizing centre (MTOC); one species in culture appears as a branched, flattened sheet without subpseudopodia; at least one species sporocarpic and protosteloid.
- Incertae sedis Centramoebida: one undescribed protosteloid LHI05, sister to Protacanthamoeba, and perhaps also Protostelium arachisporum and Protostelium pyriformis.
Submitted by Ferry on Oct. 27, 2016