[2] Members of this phylum are characterized by the presence of a helix or a double helix/ring system in the ciliary transition region.

[1] Gyrista was first described in 1998 by protistologist Thomas Cavalier-Smith in his work A revised six-kingdom system of life, originally as a superphylum containing two phyla: Ochrophyta, the heterokont algae; and Bigyra, which then contained the pseudofungi and bigyromonads together with the opalines.

[1] Later, the name Bigyra was modified to contain opalines, bicosoecids and labyrinthulomycetes, while the Ochrophyta, Pseudofungi and Bigyromonada remained as groups within Gyrista.

[2] Gyrista was seen in 2017 as the sister group to phylum Bigyra, which contains the Sagenista and Opalozoa.

The "Bigyra" is paraphyletic:[5] Opalozoa Sagenista Developea Pirsonea Pseudofungi Ochrophyta The 2018 revised taxonomy of Gyrista is the following,[2] with the inclusion of new ochrophyte classes described in 2020[6] and 2021:[7]