Data from: Hemimastigophora is a novel supra-kingdom-level lineage of Eukaryotes

Almost all eukaryote life forms have now been placed within one of five to
eight supra-kingdom-level groups using molecular phylogenetics1,2,3,4. The
‘phylum’ Hemimastigophora is probably the most distinctive morphologically
defined lineage that still awaits such a phylogenetic assignment. First
observed in the nineteenth century, hemimastigotes are free-living
predatory protists with two rows of flagella and a unique cell
architecture5,6,7; to our knowledge, no molecular sequence data or
cultures are currently available for this group. Here we report
phylogenomic analyses based on high-coverage, cultivation-independent
transcriptomics that place Hemimastigophora outside of all established
eukaryote supergroups. They instead comprise an independent
supra-kingdom-level lineage that most likely forms a sister clade to the
‘Diaphoretickes’ half of eukaryote diversity (that is, the ‘stramenopiles,
alveolates and Rhizaria’ supergroup (Sar), Archaeplastida and Cryptista,
as well as other major groups). The previous ranking of Hemimastigophora
as a phylum understates the evolutionary distinctiveness of this group,
which has considerable importance for investigations into the deep-level
evolutionary history of eukaryotic life—ranging from understanding the
origins of fundamental cell systems to placing the root of the tree. We
have also established the first culture of a hemimastigote (Hemimastix
kukwesjijk sp. nov.), which will facilitate future genomic and
cell-biological investigations into eukaryote evolution and the last
eukaryotic common ancestor.