Opalinata is a superclass of non-phagotrophy Heterokonta that unites the classes Opalinea and Blastocystea, and is the sister group to Opalomonadea.
Description
When
Opalinata was first erected as a taxon in 1926, it was placed as the sole class in the group "Protociliata" and considered as primitive
due to the fact that they move thanks to their numerous
cilia and that they both present two nuclei.
They were distinguished because they perform
syngamy by the complete fusion of uninucleated gametes, while the rest of the ciliates, forming "Euciliata" (
Ciliate +
Suctoria), perform
syngamy through their micronuclei alone while their macronuclei dissolve.
The taxon Opalinata was revised in 1996 by Cavalier-Smith and placed in Opalozoa, and is now defined by the following synapomorphy: gut parasitism and the loss of peroxisome and phagocytosis.
Phylogeny
The cladogram below shows the relationships between Opalinata and the rest of
Opalozoa.
Classification
The modern taxonomy of Opalinata is as follows:
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Phylum Bigyra
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Subphylum Opalozoa Cavalier-Smith, 1991 stat. n. 2006 em.
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Infraphylum Placidozoa Cavalier-Smith 2013
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Superclass Opalinata Wenyon, 1926 em. Cavalier-Smith, 1996 stat. n. 2006
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Class Opalinea Wenyon, 1926 stat. n. Cavalier-Smith, 1993 em. 2013
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Order Proteromonadida Grassé, 1952 em. Cavalier-Smith, 1993
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Order Opalinida Poche, 1913 stat. n. Hall, 1953 em. Cavalier-Smith
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Class Blastocystea Zierdt et al., 1967
