Opalozoa

Opalozoa is a subphylum of heterotrophic protists of the phylum Bigyra, and is the sister group to Sagenista. Opalozoans are non-photosynthetic heterokonts that are ancestrally phagotrophic but many times have evolved to be osmotrophic saprotrophs in the gut of vertebrate animals.

Opalozoa
Opalina ranarum, an opalozoan
Scientific classification
Domain:	Eukaryota
Clade:	Diaphoretickes
Clade:	SAR
Clade:	Stramenopiles
Phylum:	Bigyra
Subphylum:	Opalozoa Cavalier-Smith, 1991 stat. nov. 2006
Infraphyla and classes
?Pendulomonas ?Bordnamonadidae Bikosia Bikosea Placidozoa Wobblata Placididea Nanomonadea Opalomonadea Opalinata Opalinea Blastocystea

Taxonomy

History: phylum Opalozoa

In 1993 the name “Opalozoa” referred to a group of protists that was very different from what it is now. It was a phylum composed of many unrelated zooflagellates, grouped together because of the common presence of tubular mitochondrial cristae and the lack of cortical alveoli or rigid tubular ciliary hairs (retronemes). It also included the opalinids, proteomyxids and plasmodiophorids.

Cavalier-Smith's defunct phylum Opalozoa (1993)

Subphylum Proterozoa
  Class Heteromitea
    Subclass Sarcomonadia
      Superorder Jakobidea
        Order Jakobida
        Order Cercomonadida
      Superorder Thaumatomonadidea
        Order Thaumatomonadida
      Superorder Proteomyxidea
        Order Pseudosporida
        Order Leucodictyida
    Subclass Thecomonadia
      Order Apusomonadida
      Order Cryomonadida
    Subclass Anisomonadia
      Order Diphylleida
      Order Proteromonadida
  Class Phytomyxea
    Order Phagomyxida
    Order Plasmodiophorida
  Class Telonemea
    Order Telonemida
    Order Nephromycida
  Class Cyathobodonea
    Order Pseudodendromonadida
    Order Spongomonadida
    Order Kathablepharida
  Class Ebridea
    Order Ebriida

Subphylum Opalinata
  Class Opalinea
    Order Karotomorphida
    Order Opalinida

Subphylum Kinetomonada
  Class Kinetomonadea
    Order Histionida
    Order Heliomonadida

Subphylum Hemimastigophora
  Class Hemimastigea
    Order Hemimastigida

Modern classification

The modern taxonomy of Opalozoa, down to order level, is as follows:

• Subphylum Opalozoa Cavalier-Smith, 1991 stat. nov. 2006 emend. 2018
  • Infraphylum Bikosia Cavalier-Smith, 2013
    • Class Bikosea Cavalier-Smith nom. n. pro Bicosoecea Cavalier-Smith, 1986
      • Subclass Bicosidia Cavalier-Smith, 2006 orth. emend.
        • Superorder Cyathobodoniae Cavalier-Smith, 1993 emend. stat. nov. 2006
          • Order Bicoecida Grassé, 1926
          • Order Anoecida Cavalier-Smith, 1997 emend. 2006
          • Order Pseudodendromonadida Hibberd, 1985 emend. Cavalier-Smith, 2006
        • Superorder Borokiae Cavalier-Smith, 2006
          • Order Borokida Cavalier-Smith, 2006
      • Subclass Rictidia Cavalier-Smith, 2013
        • Order Rictida Cavalier-Smith, 2013
  • Infraphylum Placidozoa Cavalier-Smith, 2013
    • Superclass Wobblata Cavalier-Smith, 2006 stat. nov. 2013 [paraphyletic]
      • Class Placididea Moriya, Nakayama & Inouye, 2002
        • Order Placidida Moriya, Nakayama & Inouye, 2002 [=Placidae Cavalier-Smith, 2006]
      • Class Nanomonadea Cavalier-Smith, 2013
        • Order Uniciliatida Cavalier-Smith, 2013
      • Class Opalomonadea Cavalier-Smith, 2013
    • Superclass Opalinata Wenyon, 1926 emend. Cavalier-Smith, 1996 stat. nov. 2006
      • Class Opalinea Wenyon, 1926 stat. nov. Cavalier-Smith, 1993 emend. 2013
        • Order Proteromonadida Grassé, 1952 emend. Cavalier-Smith, 1993
        • Order Opalinida Poche, 1913 stat. nov. Hall, 1953 emend. Cavalier-Smith
      • Class Blastocystea Zierdt et al., 1967
        • Order Blastocystida Zierdt, 1978
• Opalozoa incertae sedis:
  • Pendulomonas Tong, 1977
  • Bordnamonadidae Cavalier-Smith, 2013

Phylogeny

The cladogram below shows the internal relationships of Opalozoa.

Opalozoa	Placidozoa Opalinata Opalinea Blastocystea Opalomonadea   Nanomonadea Placididea Bikosea Pseudodendromonadida Bicoecida Anoecida Borokida Rictida	"Wobblata"