Belongs within: Sar.
Contains: Labyrinthulomycetes, Gyrista, Opalinata.
The Heterokonta are a diverse clade of eukaryotes in which motile cells typically bear two dissimilar cilia, the anterior cilium bearing mastigonemes and the posterior being smooth (Adl et al. 2019).
Characters (Adl et al. 2019, as Stramenopiles): Motile cells typically biciliate, typically with heterokont ciliation—anterior cilium with tripartite mastigonemes in two opposite rows and a posterior usually smooth cilium; tubular mitochondrial cristae; typically, four microtubular kinetosomal roots.
<==Heterokonta [Actinodinea, Bigyra, Heterokontophyta, Labyrinthulidea, Stramenipila, Stramenopiles]C-SCL15
|--Platysulcus [Platysulcea, Platysulcida, Platysulcidae]WES23
| `--P. tardusWES23
`--+--SagenistaWES23
| |--LabyrinthulomycetesC-S18
| `--Pseudophyllomitus [Eogyrea, Eogyrida, Pseudophyllomitidae]C-S18
| |--*P. granulatusC-S18
| |--P. apiculatus Sjuka 1948C-S18
| `--P. vesiculosusC-S18
`--+--+--GyristaWES23
| `--Kaonashia Weston, Eglit & Simpson 2023 [Kaonashiidae]WES23
| `--*K. insperata Weston, Eglit & Simpson 2023WES23
`--Opalozoa [Bicoecea, Bicoecia]WES23
| i. s.: Labromonas Cavalier-Smith in Cavalier-Smith & Chao 2006 [Labromonadaceae]C-SC06
| `--*L. fenchelii Cavalier-Smith in Cavalier-Smith & Chao 2006C-SC06
|--Placidozoa [Wobblata]C-S18
| | i. s.: OpalomonadeaC-S18
| |--+--OpalinataWES23
| | `--NanomonadeaWES23
| | |--Incisomonas marinaC-S18, DL-G16
| | `--SolenicolaC-S18
| `--Placidida [Placidiaceae, Placidiales, Placididae, Placididea, Placidiophyceae]WES23
| |--Pendulomonas adriperis Tong 1997C-SC06, MNI02
| |--SuigetsumonasAB19
| |--Placidia Moriya, Nakayama & Inouye 2002MNI02
| | `--*P. cafeteriopsis Moriya, Nakayama & Inouye 2002MNI02
| `--Wobblia Moriya et al. 2000AS12, MNI02
| `--W. lunataC-SC06
`--Bikosea [Bicosoecea, Bikosia, Bikosidae]C-S18
| i. s.: Acronema sippewissettensisMS98
|--+--Rictus [Rictidia]C-S18
| | `--R. lutensisWES23
| `--Cantina marsupialisWES23
`--BikosidiaC-S18
|--Boroka Cavalier-Smith in Cavalier-Smith & Chao 2006 [Borokaceae, Borokales, Borokiae, Borokida]C-SC06
| `--*B. karpovii Cavalier-Smith in Cavalier-Smith & Chao 2006C-SC06
`--Bicosoecida [Cyathobodoniae]AS12
| i. s.: HalocafeteriaAB19
|--Anoecida [Anoecales]C-S18
| |--+--Caecitellus Patterson et al. 1993 [Caecitellaceae, Caecitellida]C-SC06
| | | `--C. parvulusC-SC06
| | `--+--Symbiomonas Guillou & Chretiennot-Dinet 1999 [Symbiomonadaceae]C-SC06
| | | `--S. scintillansC-SC06
| | `--Anoeca Cavalier-Smith in Cavalier-Smith & Chao 2006 [Anoecaceae]C-SC06
| | `--*A. atlantica Cavalier-Smith & Chao 2006 [=Cafeteria minima (n. n.)]C-SC06
| `--CafeteriaceaeC-SC06
| |--PseudobodoC-S97
| | |--P. minimaC-SC06
| | |--P. minuta Ruinen 1938 [=Cafeteria minuta]C-SC06
| | `--P. tremulans Griessmann 1913C-SC06
| `--CafeteriaC-SC06
| |--C. burkhardaeTS25
| |--C. liguliferaC-SC06
| |--C. marsupialis Larsen & Patterson 1990C-SC06
| |--C. mylnikovii Cavalier-Smith & Chao 2006C-SC06
| `--C. roenbergensisC-SC06
`--+--Bicosoeca (see below for synonymy)C-SC06
| |--B. marisTSI19
| |--B. petiolataC-SC06
| |--B. planktonicaWES23 [=Bicoeca planktonicaMM98]
| `--B. vacillansC-SC06
`--Pseudodendromonadida [Pseudodendromonadales]C-S18
| i. s.: Pseudodendromonadaceae [Pseudodendromonadidae]C-SC06
| |--Pseudodendromonas Bourelly 1953C-S93
| `--Cyathobodo Petersen & Hansen 1961C-S93
| FilosC-S18
| NanumC-S18
|--Nerada Cavalier-Smith in Cavalier-Smith & Chao 2006 [Neradaceae]C-SC06
| `--*N. mexicana Cavalier-Smith & Chao 2006C-SC06
`--+--Paramonas [Paramonadaceae]C-SC06
| |--*P. globosaC-SC06
| |--P. desesC-SC06
| |--P. ovumC-SC06
| `--P. stellataC-SC06
`--+--Siluania [Siluaniaceae]C-SC06
| `--S. monomastigaC-SC06
`--Adriamonas [Adriamonadaceae]C-SC06
`--A. peritocrescensC-SC06
Bicosoeca [=Bicoeca Stein 1878; Bicoecaceae, Bicoecales, Bicoecida, Bicoecidea, Bicosoecaceae, Bicosoecidae, Bikoecida, Bikoecidae]C-SC06
*Type species of generic name indicated
References
[AB19] Adl, S. M., D. Bass, C. E. Lane, J. Lukeš, C. L. Schoch, A. Smirnov, S. Agatha, C. Berney, M. W. Brown, F. Burki, P. Cárdenas, I. Čepička, L. Chistyakova, J. del Campo, M. Dunthorn, B. Edvardsen, Y. Eglit, L. Guillou, V. Hampl, A. A. Heiss, M. Hoppenrath, T. Y. James, A. Karnkowska, S. Karpov, E. Kim, M. Kolisko, A. Kudryavtsev, D. J. G. Lahr, E. Lara, L. Le Gall, D. H. Lynn, D. G. Mann, R. Massana, E. A. D. Mitchell, C. Morrow, J. S. Park, J. W. Pawlowski, M. J. Powell, D. J. Richter, S. Rueckert, L. Shadwick, S. Shimano, F. W. Spiegel, G. Torruella, N. Youssef, V. Zlatogursky & Q. Zhang. 2019. Revisions to the classification, nomenclature, and diversity of eukaryotes. Journal of Eukaryotic Microbiology 66: 4–119.
[AS12] Adl, S. M., A. G. B. Simpson, C. E. Lane, J. Lukeš, D. Bass, S. S. Bowser, M. W. Brown, F. Burki, M. Dunthorn, V. Hampl, A. Heiss, M. Hoppenrath, E. Lara, E. Le Gall, D. H. Lynn, H. McManus, E. A. D. Mitchell, S. E. Mozley-Stanridge, L. W. Parfrey, J. Pawlowski, S. Rueckert, L. Shadwick, C. L. Schoch, A. Smirnov & F. W. Spiegel. 2012. The revised classification of eukaryotes. Journal of Eukaryotic Microbiology 59 (5): 429–493.
[C-S93] Cavalier-Smith, T. 1993. The protozoan phylum Opalozoa. Journal of Eukaryotic Microbiology 40 (5): 609–615.
[C-S97] Cavalier-Smith, T. 1997. Sagenista and Bigyra, two phyla of heterotrophic heterokont chromists. Archiv für Protistenkunde 148: 253–267.
[C-S18] Cavalier-Smith, T. 2018. Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences. Protoplasma 255: 297–357.
[C-SC06] Cavalier-Smith, T., & E. E.-Y. Chao. 2006. Phylogeny and megasystematics of phagotrophic heterokonts (kingdom Chromista). Journal of Molecular Evolution 62: 388–420.
[C-SCL15] Cavalier-Smith, T., E. E. Chao & R. Lewis. 2015. Multiple origins of Heliozoa from flagellate ancestors: new cryptist subphylum Corbihelia, superclass Corbistoma, and monophyly of Haptista, Cryptista, Hacrobia and Chromista. Molecular Phylogenetics and Evolution 93: 331–362.
[DL-G16] Derelle, R., P. López-García, H. Timpano & D. Moreira. 2016. A phylogenomic framework to study the diversity and evolution of stramenopiles (=heterokonts). Molecular Biology and Evolution 33 (11): 2890–2898.
[MS98] Margulis, L., & K. V. Schwartz. 1998. Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth 3rd ed. W. H. Freeman and Company: New York.
[MM98] Mikrjukov, K. A., & A. P. Mylnikov. 1998. The fine structure of a carnivorous multiflagellar protist, Multicilia marina Cienkowski, 1881 (Flagellata incertae sedis). European Journal of Protistology 34: 391–401.
[MNI02] Moriya, M., T. Nakayama & I. Inouye. 2002. A new class of the stramenopiles, Placididea classis nova: description of Placidia cafeteriopsis gen. et sp. nov. Protist 153: 143–156.
[TS25] Terpis, K. X., E. D. Salomaki, D. Barcytė, T. Pánek, H. Verbruggen, M. Kolisko, J. C. Bailey, M. Eliáš & C. E. Lane. 2025. Multiple plastid losses within photosynthetic stramenopiles revealed by comprehensive phylogenomics. Current Biology 35: 483–499.
[TSI19] Thakur, R., T. Shiratori & K. Ishida. 2019. Taxon-rich multigene phylogenetic analyses resolve the phylogenetic relationships among deep-branching stramenopiles. Protist 170: 125682.
[WES23] Weston, E. J., Y. Eglit & A. G. B. Simpson. 2023. Kaonashia insperata gen. et sp. nov., a eukaryotrophic flagellate, represents a novel major lineage of heterotrophic stramenopiles. Journal of Eukaryotic Microbiology 71: e13003.