The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes.
[1] They include genera that are internal parasites or commensals of animals (Entamoeba and Endolimax).
The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella.
[3][4] Early molecular trees based on rRNA supported this position, placing several Archamoebae genera as separate groups that diverged from other eukaryotes very early on, suggesting that the absence of mitochondria was a primitive condition.
[2] Entamoebidae Mastigamoebidae Rhizomastixidae Pelomyxidae Infraphylum Archamoebae Cavalier-Smith 1993 stat.