Hemimastigophora

Hemimastigophora is a group of single-celled eukaryotic organisms.[3] It was established in 1988 by Foissner et al., as a new phylum with a single family, Spironemidae.[1] Its placement on the eukaryote tree of life was unclear, but the authors suggested that the structure of its pellicle and cell nucleus indicated a close relationship with Euglenozoa. For thirty years after the classification of the group, no genetic information was available. During that time, researchers proposed that it should be classified in, or near, an assortment of other groups, including the alveolates, apusomonads, ancyromonads, and Rhizaria.[3]

Hemimastigophora
Hemimastix amphikineta, redrawn from Foissner et al., 1988[1]
Scientific classification
Domain:	Eukaryota
(unranked):	Hemimastigophora Foissner, Blatterer & Foissner 1988 sensu Cavalier-Smith 1993[2]
Classes, orders, families and genera
Hemimastigea Foissner, Blatterer & Foissner 1988 Hemimastigida Foissner, Blatterer & Foissner 1988 Spironemidae Reichenow 1928 Hemimastix Foissner, Blatterer & Foissner 1988 Paramastix Skuja 1948 Spironema Klebs 1893 Stereonema Foissner & Foissner 1993

In an article published in 2018, it was announced that a new hemimastigophoran species, Hemimastix kukwesjijk, had been discovered in a Nova Scotian soil sample, and successfully cultivated in the laboratory. A second hemimastigophoran, a new species of Spironema, was found in the same sample. Phylogenomic analyses of the two organisms suggest that Hemimastigophora is a very ancient lineage, which diverged from the other eukaryotes at such an early date that the group should be classified at the supra-kingdom level.[3]