Class Granofilosea Cavalier-Smith and Bass, 2009

 

Diagnosis: Cercozoa typically with very fine branching or unbranched filopodia bearing obvious granules (extrusomes) at frequent rather regular intervals or with radiating axopodia (some­times branched) with similar granules; filopodia with internal microtubules, typically appressed to the substratum during feeding, in a semi-immobile state; in most species they do not anastomose but in a few they may, especially between separate cells to form a meroplasmodium (notably in Leucodictyidae; possibly also in Massisteria); characterised species bacterivorous, marine or freshwater. Many have paired centrioles and either two ciliary stubs or two short cilia in the feeding phase or even a distinct flagellate phase (Massis­teria marina, probably Limnofila borokensis, Meso­fila limnetica, desmothoracids) with one or two long cilia. Golgi dictyosomes paranuclear; ciliary transition region with an axosome at the base of the central pair.

 

Order 1. Limnofilida Cavalier-Smith and Bass, 2009

Diagnosis: Small freshwater heterotrophic protozoa with extremely slender, branching gran­ular filopodia, appressed to the substratum during feeding. Phylogenetically defined as the largest clade that includes Limnofila but excludes Mas­sisteria. It excludes the phylogenetically distant marine Nanofila which is morphologically similar but with unbranched filopodia.

 

Family 1. Limnofilidae Cavalier-Smith and Bass, 2009

Diagnosis: trophic phase a small, often globular cell; cilia if present generally not visible in the light microscope; with branched regularly granular and very slender filopodia. Bacterivorous.
Type genus Limnofila Cavalier-Smith and Bass, 2009

 

Order 2. Leucodictyida Cavalier-Smith, 1993.

Diagnosis: Biciliate marine protists with very slender branching granular filopodia that can fuse temporarily to form meroplasmodia; granules are concentric extrusomes; tubular mitochondrial cristae; large granules in the distal centriolar matrix (a synapomorphy not remarked on before); with (Massisteria) or without (Leucodictyidae: Leucodictyon, Reticulamoeba) obvious paranuc­lear microbody.

 

Order 3. Cryptofilida Cavalier-Smith and Bass, 2009

Diagnosis: non-ciliate heterotrophic pro­tists with branching or unbranched granular filopodia appressed to the substratum during feeding. If filopodia branch, cells are larger than Limnofilida.

 

Family 1. Nanofilidae Cavalier-Smith and Bass fam. n. Diagnosis: tiny non-ciliate marine hetero­trophic protists with unbranched granular filopodia appressed to the substratum during feeding. Type genus Nanofila Cavalier-Smith and Bass gen. nov. Diagnosis: tiny non-ciliate marine hetero­trophic protists with unbranched granular filopodia appressed to substratum during feeding. Type species Nanofila marina Cavalier-Smith and Bass, 2009

 

Family 2. Mesofilidae Cavalier-Smith and Bass, 2009

Diagnosis: Biciliate amoeboflagellates with numerous extremely long branching filopodia that in contrast to Heliomorphidae (Tetradimorpha and Heliomorpha — usually known by the invalid names Dimorpha or Dimorphiella) do not radiate in three dimensions from a centrosome but are appressed to the substratum during feeding. Filopodia and long cilia can be present simulta­neously or each on their own, depending on the growth phase. Type genus Mesofila Cavalier-Smith and Bass gen. n. Diagnosis as for family Mesofilidae.
Type species Mesofila limnetica Cavalier-Smith and Bass, 2009

 

Order 4. Clathrulinidae Claus, 1874

Diagnosis: Extracellular capsule or lorica attached to substrate, with axopodia emerging from perforations; kinetocyst extrusomes along axopodia; tubular mitochondrial cristae; biciliated and
amoeboid stages; can be colonial. Cienkowskia, Clathrulina, Hedriocystis.

 

Order 5. Heliomonadida Cavalier-Smith 1993 ( = Dimorphida Siemensma 1991)

 

Family Heliomorphidae Cavalier-Smith and Bass, 2009

Diagnosis: Biciliate freshwater hetero­trophic Cercozoa with axopodia radiating three dimensionally from a centrosome and supported by microtubules cross-linked in a quincunx pat­tern; centrioles exceptionally long; axopodia have fairly regularly spaced complex extrusomes with a concentric core. Anterior cilium bears fine hairs in at least one genus; ciliary transition region more complex than in other Granofilosea, with a second distal transverse plate well distal to the centriolar distal partition, a peripheral dense cylinder and axosome. The centrosome is embedded in a deep depression at the anterior end of the nucleus and some axopodial axonemes penetrate the nuclear cup via cytoplasmic channels.
Type genus Helio­morpha Cavalier-Smith and Bass, 2009

 

Family Tetradimorphidae

 

Class Proteomyxidea Lankester, 1885 emend. Cavalier-Smith and Bass, 2009

Diagnosis: Naked cercozoan rhizopods with non-granular filopodia or (more usually) reticulopodia; plastids absent; cilia usually absent. Feeding stage uninucleate or multinucleate, sometimes numerous cells form a macroscopic plasmodium. Phagotrophic; feed on bacteria, fungi, algae or small animals. Marine or freshwater or in soil or among mosses or lichens.