Description of Euglenozoa:
Circumscription: Flagellates with two flagella inserting into an anterior pocket. Two basal bodies giving rise to three microtubular rootlets, free living or parasitic, autotrophs, heterotrophs, and mixotrophs. Mostly with discicristate mitochondria and possibly distantly related to other taxa (Stephanopogon, Hemimastigophora, nucleariids, and Heterolobosea) with discicristate mitochondria. Ultrastructural identity: Well studied, with two flagella, flagella typically inserting parallel or nearly so, giving rise to three microtubular ribbons, one of which associated with actual or presumptive ingestion device. Flagella with paraxonemal rods, the dorsal (anterior) flagellum with a tubular paraxonemal rod, and the ventral (recurrent) flagellum with a paraxonemal rod with a lattice structure. Flagella often with fine hairs. Extrusomes with lattice walls when extruded and a cruciate pattern when not. Mitochondrial cristae typically disc shaped with short pedicel; some (kinetoplastids) with aggregates of DNA. Cell surface naked or with strips of cytoskeletal material (euglenids). Nuclear envelope intact during mitosis, spindle microtubules internal. Synapomorphy: Discicristate protists with heteromorphic paraxonemal rods (dorsal flagellum with tubular rod, ventral with lattice structure).