Order Thecamoebida  Schaeffer, 1926, sensu Smirnov et al. 2011

Diagnosis: Flattened amoebae, oblong, lingulate or irregularly triangular amoebae, usually with dorsal folds and/or ridges; anterior hyaloplasm often forms an anterolateral crescent and rarely occupies more than half of the body length; never produce discrete pseudopodia or subpseudopodia.

Sappinia, Pseudothecamoeba, Thecamoeba, Thecochaos, Stratorugosa.