Phylogenetic scheme III.
 root
Hexamastix
Tricercomitus
Free-living +
Monocercomonas
ruminantium
Trichonymphidae
Eucomonymphidae
Hypotrichomonas
Trichomitus
Spirotrichonymphidae +
Holomastigotoididae
Calonymphidae +
Devescovinidae
Dientamoeba +
Histomonas
Tritrichomonadinae
Monocercomonas sp.
Trichomonadinae