Opalozoa

Opalozoa is a subphylum of heterotrophic protists of the phylum Bigyra, and is the sister group to Sagenista.^[6][1] Opalozoans are non-photosynthetic stramenopiles that are ancestrally phagotrophic but many times have evolved to be osmotrophic saprotrophs in the gut of vertebrate animals.^[7]

Opalozoa
Opalina ranarum, an opalozoan
Scientific classification
Domain:	Eukaryota
Clade:	Sar
Clade:	Stramenopiles
Phylum:	Bigyra
Subphylum:	Opalozoa Cavalier-Smith, 1991 stat. nov. 2006[1]
Subgroups[2][3][4][5]
Pendulomonas? Bordnamonadidae? Placidozoa Nanomonadea Placididea Opalomonadea Opalinata Opalinea Blastocystea Bikosia Bikosea

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.^[8]

Cavalier-Smith's defunct phylum Opalozoa (1993)^[8]

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:^[1]

• 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
    • 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.^[1]

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