euglenozoa euglenozoa euglenozoa are a large group of flagellate discoba. they include a variety of common free-living species, as well as a few important parasites, some of which infect humans. euglenozoa are represented by four major groups, i.e., kinetoplastea, diplonemea, euglenida, and symbiontida. euglenozoa are unicellular, mostly around 15–40 μm (0.00059–0.00157 in) in size, although some euglenids get up to 500 μm (0.020 in) long. euglenozoa two euglena scientific classification domain: eukaryota superphylum: discicristata phylum: euglenozoacavalier-smith, 1981 classes diplonemea euglenida kinetoplastea symbiontida (postgaardia) structure most euglenozoa have two flagella, which are inserted parallel to one another in an apical or subapical pocket. in some these are associated with a cytostome or mouth, used to ingest bacteria or other small organisms. this is supported by one of three sets of microtubules that arise from the flagellar bases; the other two support the dorsal and ventral surfaces of the cell. some other euglenozoa feed through absorption, and many euglenids possess chloroplasts, the only eukaryotes outside diaphoretickes to do so without performing kleptoplasty, and so obtain energy through photosynthesis. these chloroplasts are surrounded by three membranes and contain chlorophylls a and b, along with other pigments, so are probably derived from a green alga, captured long ago in an endosymbiosis by a basal euglenozoan. reproduction occurs exclusively through cell division. during mitosis, the nuclear membrane remains intact, and the spindle microtubules form inside of it. the group is characterized by the ultrastructure of the flagella. in addition to the normal supporting microtubules or axoneme, each contains a rod (called paraxonemal), which has a tubular structure in one flagellum and a latticed structure in the other. based on this, two smaller groups have been included here: the diplonemids and postgaardi. classification the euglenozoa are generally accepted as monophyletic. they are related to percolozoa; the two share mitochondria with disk-shaped cristae, which only occurs in a few other groups. both probably belong to a larger group of eukaryotes called the excavata. this grouping, though, has been challenged. phylogeny the phylogeny based on the work of cavalier-smith (2016): euglenozoa phylogeny – cavalier-smith (2016) glycomonada diplonemea diplonemida hemistasiidae eupelagonemidae diplonemidae kinetoplastea prokinetoplastina ichthyobodonidae metakinetoplastina rhynchobodo neobodonidae parabodonidae bodonidae trypanosomatidae plicomonada postgaardia postgaardea bihospitida bihospitidae postgaardida postgaardidae calkinsiidae euglenoida entosiphona entosiphonea entosiphonida entosiphonidae dipilida stavomonadea heterostavia heterostavida serpenomonadidae homostavia decastavida decastavidae keelungiidae petalomonadida sphenomonadidae petalomonadidae ploeotarea ploeotiida lentomonadidae ploeotiidae spirocuta peranemida peranemidae anisonemida anisonemidae natomonadida metanemina neometanemidae rhabdomonadina distigmidae astasiidae acroglissida teloproctidae euglenophyceae rapazida rapazidae eutreptiales eutreptiaceae euglenales euglenamorphaceae phacaceae euglenaceae peranemea(paraphyletic) a consensus phylogeny following the review by kostygov et al. (2021): euglenozoa phylogeny – kostygov et al. (2021) glycomonada kinetoplastea prokinetoplastia prokinetoplastida ichthyobodonidae perkinselidae metakinetoplastia neobodonida allobodonidae neobodonidae rhynchomonadidae parabodonida cryptobiidae trypanoplasmatidae eubodonida bodonidae trypanosomatida trypanosomatidae diplonemea diplonemida diplonemidae eupelagonemidae hemistasiidae "euglenids" euglenida petalomonadida alistosa olkaspira olkasia spirocuta anisonemia anisonemidae aphagea euglenophyceae rapazida rapazidae eutreptiaceae/eutreptiidae euglenales euglenaceae/euglenidae phacaceae/phacidae peranemida symbiontida bihospites calkinsia postgaardi cavalier-smith (2016/2017) the following classification of euglenozoa is as described by cavalier-smith in 2016, modified to include the new subphylum plicomonada according to cavalier-smith et al (2017). phylum euglenozoa cavalier-smith 1981 emend. simpson 1997 subphylum glycomonada cavalier-smith 2016 class diplonemea cavalier-smith 1993 emend. simpson 1997 order diplonemida cavalier-smith 1993 family hemistasiidae cavalier-smith 2016 family diplonemidae cavalier-smith 1993 class kinetoplastea honigberg 1963 emend. margulis 1974 subclass prokinetoplastina vickerman 2004 order prokinetoplastida vickerman 2004 family ichthyobodonidae isaksen et al., 2007 subclass metakinetoplastina vickerman 2004 order bodonida* hollande 1952 em. vickerman 1976, kryov et al 1980 suborder neobodonida vickerman 2004 family rhynchomonadidae cavalier-smith 2016 family neobodonidae cavalier-smith 2016 suborder parabodonida vickerman 2004 family parabodonidae cavalier-smith 2016 family cryptobiidae* vickerman 2004 suborder eubodonida vickerman 2004 family bodonidae bütschli 1883 order trypanosomatida kent 1880 stat. n. hollande, 1952 emend. vickerman 2004 family trypanosomatidae doflein 1901 subphylum plicomonada cavalier-smith 2017 infraphylum postgaardia cavalier-smith 2016 stat. nov. cavalier-smith 2017 class postgaardea cavalier-smith 1998 s.s. order bihospitida cavalier-smith 2016 family bihospitidae cavalier-smith 2016 order postgaardida cavalier-smith 2003 family calkinsiidae cavalier-smith 2016 family postgaardidae cavalier-smith 2016 infraphylum euglenoida bütschli 1884 emend. senn 1900 stat. nov. cavalier-smith, 2017 parvphylum entosiphona cavalier-smith 2016 stat. nov. cavalier-smith 2017 class entosiphonea cavalier-smith 2016 order entosiphonida cavalier-smith 2016 family entosiphonidae cavalier-smith 2016 parvphylum dipilida cavalier-smith 2016 stat. nov. cavalier-smith 2017 superclass rigimonada* cavalier-smith 2016 class stavomonadea cavalier-smith 2016 subclass heterostavia cavalier-smith 2016 order heterostavida cavalier-smith 2016 family serpenomonadidae cavalier-smith 2016 subclass homostavia cavalier-smith 2016 order decastavida cavalier-smith 2016a family decastavidae cavalier-smith 2016a family keelungiidae cavalier-smith 2016a order petalomonadida cavalier-smith 1993 family sphenomonadidae kent 1880 family petalomonadidae class ploeotarea cavalier-smith 2016 order ploeotiida cavalier-smith 1993 family lentomonadidae cavalier-smith 2016 family ploeotiidae cavalier-smith 2016 superclass spirocuta cavalier-smith 2016 class peranemea cavalier-smith 1993 emend. cavalier-smith 2016 subclass acroglissia cavalier-smith 2016 order acroglissida cavalier-smith 2016 family teloproctidae cavalier-smith 2016a subclass peranemia cavalier-smith 2016 order peranemida bütschli 1884 stat. nov. cavalier-smith 1993 family peranematidae subclass anisonemia cavalier-smith 2016 order anisonemida cavalier-smith 2016 family anisonemidae saville kent, 1880 em. cavalier-smith 2016 order natomonadida cavalier-smith 2016 suborder metanemina cavalier-smith 2016 family neometanemidae cavalier-smith 2016 suborder rhabdomonadina leedale 1967 emend. cavalier-smith 1993 family distigmidae hollande, 1942 family astasiidae saville kent, 1884 class euglenophyceae schoenichen 1925 emend. marin & melkonian 2003 (photosynthetic clade) subclass rapazia cavalier-smith 2016 order rapazida cavalier-smith 2016 family rapazidae cavalier-smith 2016 subclass euglenophycidae busse and preisfeld, 2003 order eutreptiida family eutreptiaceae order euglenida ritter von stein, 1878 stat. n. calkins, 1926 family euglenamorphidae hollande, 1952 stat. n. cavalier-smith 2016 family phacidae family euglenidae bütschli 1884 (mucilaginous clade) kostygov et al. (2021) phylum euglenozoa cavalier-smith 1981 emend. simpson 1997 class kinetoplastea honigberg, 1963 emend. vickerman, 1976 subclass prokinetoplastia vickerman, 2004 order prokinetoplastida vickerman, 2004 family ichthyobodonidae isaksen et al., 2007 family perkinselidae kostygov, 2021 subclass metakinetoplastia vickerman, 2004 order eubodonida vickerman 2004 family bodonidae bütschli, 1883 order neobodonida vickerman, 2004 family allobodonidae goodwin et al., 2018 family neobodonidae cavalier-smith, 2016 family rhynchomonadinae cavalier-smith, 2016 order parabodonida vickerman, 2004 family cryptobiidae poche, 1911 emend. kostygov, 2021 family trypanoplasmatidae hartmann and chagas, 1910 emend. kostygov, 2021 order trypanosomatida kent, 1880 family trypanosomatidae doflein, 1901 class diplonemea cavalier-smith, 1993 order diplonemida cavalier-smith, 1993 family diplonemidae cavalier-smith, 1993 family hemistasiidae cavalier-smith, 2016 family eupelagonemidae okamoto and keeling, 2019 class euglenida bütschli, 1884 emend. simpson, 1997 clade olkaspira lax and simpson, 2020 clade spirocuta cavalier-smith, 2016 clade euglenophyceae schoenichen, 1925 emend. marin and melkonian, 2003 order euglenales leedale, 1967 emend. marin and melkonian, 2003 family euglenaceae dujardin, 1841 emend. kim et al., 2010 family phacaceae kim, triemer and shin 2010 family eutreptiaceae hollande, 1942 order rapazida cavalier-smith, 2016 family rapazidae cavalier-smith, 2016 clade anisonemia cavalier-smith, 2016 order anisonemida cavalier-smith, 2016 family anisonemidae kent, 1880 clade aphagea cavalier-smith, 1993 emend. busse and preisfeld, 2002 order peranemida cavalier-smith, 1993 clade alistosa lax et al., 2020 order petalomonadida cavalier-smith, 1993 class symbiontida yubuki, edgcomb, bernhard and leander, 2009