apusozoa apusozoa the apusozoa are an obazoa phylum comprising several genera of flagellate eukaryotes. they are usually around 5–20 μm in size, and occur in soils and aquatic habitats, where they feed on bacteria. they are grouped together based on the presence of an organic shell or theca under the dorsal surface of the cell. for an explanation of very similar terms, see obazoa. apusozoa apusomonas sp. scientific classification clade: obazoa phylum: apusozoacavalier-smith 1997 em. orders apusomonadida breviata the name derives from the ancient greek words for footless (ἄπους) and animal (ζῷον). this phylum is currently defined as containing the breviata and the apusomonadida. however, it currently usually is viewed as paraphyletic, with the breviata as more basal. the opisthokonts appear to have emerged as sister of the apusomonadida. it has been suggested that the mantamonadida be classified in apusozoa. the ancyromonadida appear to be varisulca, planomonadida, shifting them possibly more basal than the amoebozoa, or less basal. while some classification systems have placed hemimastigida in apusozoa, 2018 research indicated that hemimastigotes (hemimastix kukwesjijk/hemimastix/spironemidae) are their own supra-kingdom. characteristics the apusomonads have two flagella inserted at right angles, near the anterior of the cell. they move by gliding, with one flagellum trailing along the side and one directed to the anterior. the form of the mitochondria varies between the different orders. among the apusomonads they have tubular cristae, the ancyromonads flat cristae, and the hemimastigids ambiguous or sacculate cristae. this characteristic was originally considered a good indicator of relationships, but is now known to vary even among close relatives. eukaryotes diphoda diaphoretickes cryptista archaeplastida rhodophyta (red algae) picozoa glaucophyta viridiplantae (plants) 1600 mya haptista tsar telonemia sar halvaria stramenopiles alveolata rhizaria provora hemimastigophora discoba ? metamonada bikonts ancyromonadida malawimonada crums amorphea amoebozoa obazoa breviatea apusomonadida opisthokonta holomycota (inc. fungi) holozoa (inc. animals) 1300 mya 1500 mya 2200 mya one view of the great kingdoms and their stem groups.