breviatea breviatea breviatea are a group of free-living, amitochondriate parasitic protists with uncertain phylogenetic position. they are biflagellate, and can live in anaerobic (oxygen-free) environments. they are currently placed in the proposed obazoa clade. they likely do not possess vinculin proteins. their metabolism relies on fermentative production of atp as an adaptation to their low-oxygen environment. breviatea breviata anathema scientific classification clade: obazoa class: breviateacavalier-smith, chao, & oates, 2003 the lineage emerged roughly one billion years ago, at a time when the oxygen content of the earth's oceans were low, and they thus developed anaerobic lifestyles. together with apusomonads, they are the closest relatives of the opisthokonts, a group that includes animals and fungi. cladogram of breviatidae breviata anathema subulatomonas tetraspora lenisia limosa pygsuia biforma species family breviatidae breviata breviata anathema lenisia lenisia limosa pygsuia pygsuia biforma subulatomonas subulatomonas tetraspora