During locomotion most Tubulinea have a roughly cylindrical form or produce numerous cylindrical pseudopods. Each cylinder advances by a single central stream of cytoplasm, granular in appearance, and has no subpseudopodia. This distinguishes them from other amoeboid groups, although in some members this is not the normal type of locomotion.
This class was anticipated by some biologists like Jahn, who grouped all amoebae with granular pseudopodia together, but most split the lobose amoebae into testate Testacealobosia and naked Gymnamoebia. These latter are polyphyletic, but molecular trees by Bolivar et al. identified a core monophyletic subgroup. Subsequent studies showed the testate lobose amoebae belong to the same group, which was thus renamed Lobosea sensu stricto or Tubulinea.