Cercozoa

Cercozoa
Cercomonas
Scientific classification
Domain:	Eukaryota
Clade:	Diaphoretickes
Clade:	SAR
Clade:	Rhizaria
Phylum:	Cercozoa Cavalier-Smith, 1998[1] emend. Adl et al., 2005 emend. Cavalier-Smith, 2018[2]
Classes
Monadofilosa Eoglissa Metromonadea Helkesea Ventrifilosa Thecofilosea Imbricatea Sarcomonadea Reticulofilosa Chlorarachnea Granofilosea Skiomonadea?
Synonyms
Cavalier-Smith, 1996[3] Filosa Cavalier-Smith & Chao, 2003

Cercozoa (now synonymised with Filosa)

Some cercozoans are grouped by whether they are "filose" or "reticulose" in the behavior of their cytoskeleton when moving:^[10]

• Filose, meaning their
  pseudopods develop as filopodia
  . For example:
  • siliceous
    scales or plates, which are commonly found in soils, nutrient-rich waters, and on aquatic plants.
  • Gromia, a shelled amoeba.
  • Tectofilosids, filose amoebae that produce organic shells.
  • Cercomonads, common soil-dwelling amoeboflagellates.
• Reticulose, meaning they form a reticulating net of
  pseudopods
  . For example:
  • Chlorarachniophytes, set apart by the presence of chloroplasts bound by four membranes and still possess a vestigial nucleus, called a nucleomorph. As such, they have been of great interest to researchers studying the endosymbiotic origins of organelles.

Other important ecological groups are:

• Gymnosphaerida.^[10]
• Phaeodaria, marine protozoa previously considered radiolarians.^[11]

However, the monophyly of the group was still uncertain. Posterior multigene phylogenetic analyses consistently found Cercozoa to be paraphyletic, because Endomyxa clustered next to Retaria instead of Filosa.^[17][18][19] Because of this, Endomyxa was excluded from Cercozoa, which became a synonym of Filosa.^[2]

More recent phylogenomic analyses with better sampling recovered a sister relationship between Filosa (=Cercozoa) and Endomyxa once again,^[15] although the modern classification of eukaryotes retains Endomyxa, Cercozoa and Retaria as separate phyla within Rhizaria.^[20]

Internal evolution

The phylum Cercozoa previously contained both Filosa and

The classification of Cercozoa was revised in 2018:[2]

• Subphylum Reticulofilosa Cavaler-Smith 1997
  • Class
    Chlorarachniophyceae
    )
  • Class Granofilosea Cavalier-Smith & Bass 2009
  • Class Skiomonadea Cavalier-Smith 2012
• Subphylum Monadofilosa Cavalier-Smith 1997
  • Superclass Eoglissa Cavalier-Smith 2011 emend. 2018
    • Class Metromonadea Cavalier-Smith 2007
    • Class
      Helkesea
      Cavalier-Smith 2018
  • Superclass Ventrifilosa Cavalier-Smith 2012 emend. 2018
    • Class Sarcomonadea Cavalier-Smith 1993 emend. 2018
    • Class Imbricatea Cavalier-Smith 2003 emend. 2018
      
    • Class Thecofilosea Cavalier-Smith 2003 emend. 2012
      

Gallery

• 
  Cercomonas sp. (Cercozoa:

  Cercomonadida

  )
• 
  Ebria sp. (Cercozoa:

  Ebridea

  )
• 
  Rhipidodendron sp. (Cercozoa:

  Spongomonadea

  )
• 
  Euglypha sp. (Cercozoa: Euglyphida)
• 
  Phaeodarians (Cercozoa: Phaeodarea)
• 
  Desmothoracida

  )
• 
  Chlorarachniophyta

  )
• 
  Vampyrella sp. (Cercozoa: Vampyrellidae)
• 
  Orciraptor agilis (Viridiraptoridae) attacking Mougeotia sp. (Zygnemataceae)
• 
  Gromiidea

  )
• 
  Auranticordis (Cercozoa: Marimonadida)