Amastigomonas is a genus of protists belonging to a lineage of biciliated zooflagellates known as Apusomonadida. It was first described in 1931 by Henri de Saedeleer. The current use of Amastigomonas is as a descriptive archetype, with no phylogenetic or taxonomic implications. The term "Amastigomonas-like" is used to refer to all apusomonads that lack the 'derived' characteristics of Apusomonas.
Organisms under the name "Amastigomonas" have an oval or oblong cell that can generate pseudopodia from the ventral surface. They lack a mastigophore, a projection of the cell body that contains both basal bodies at its end. Like all Apusomonadida, they have two flagella, and the anterior flagellum is surrounded by a membranous sleeve.
Current use of the name
Historically, the name Amastigomonas was used for any apusomonad spec