An ultrastructural study of a free-living retortamonad, Chilomastix cuspidata (Larsen & Patterson, 1990) n.
CAVALIER-SMITH: Mitch Sogin presented data at another conference in which he had a retortamonad as a sister group to diplomonads on a ribosomal RNA tree, and unless I am mistaken, that would be molecular evidence for two of the three Metamonad groups actually belonging together.
These purportedly primitively amitochondriate protists included the microsporidia, pelobionts, diplomonads, retortamonads, oxymonads, entamoebae, trichomonads, and other parabasalids.
Largely because of the lack of appropriate investigations, there is no evidence that retortamonads or oxymonads have had a mitochondriate ancestry.
The organization of Trimastix differs from that of all well-circumscribed groups but shares features with the retortamonads, jakobids (15), and Carpediemonas (see below).