Loukozoa

{{Short description|Proposed taxon}}

{{Automatic taxobox

| image = Malawimonasms.jpg

| image_caption = Malawimonasms

|taxon = Loukozoa

| subdivision_ranks = Subgroups

| subdivision = *Neolouka/Malawimonadea

• Metamonada
• Ancyromonadida?

| authority = Cavalier-Smith, 1999{{Cite journal

| last1 = Cavalier-Smith | first1 = T.

| title = Principles of protein and lipid targeting in secondary symbiogenesis: Euglenoid, dinoflagellate, and sporozoan plastid origins and the eukaryote family tree

| journal = The Journal of Eukaryotic Microbiology

| volume = 46

| issue = 4

| pages = 347–366

| year = 1999

| pmid = 18092388

| doi=10.1111/j.1550-7408.1999.tb04614.x

| s2cid = 22759799

}}

}}

Loukozoa (From Greek loukos: groove) is a proposed taxon used in some classifications of eukaryotes, consisting of the Metamonada and Malawimonadea.{{Cite journal|last=Cavalier-Smith|first=Thomas|title=Euglenoid pellicle morphogenesis and evolution in light of comparative ultrastructure and trypanosomatid biology: semi-conservative microtubule/strip duplication, strip shaping and transformation|journal=European Journal of Protistology|volume=61|issue=Pt A|pages=137–179|doi=10.1016/j.ejop.2017.09.002|pmid=29073503|year=2017|doi-access=free}} Ancyromonads are closely related to this group, as sister of the entire group, or as sister of the Metamonada. Amorphea may have emerged in this grouping, specifically as sister of the Malawimonads.{{Cite journal|last1=Lax|first1=Gordon|last2=Eglit|first2=Yana|last3=Eme|first3=Laura|last4=Bertrand|first4=Erin M.|last5=Roger|first5=Andrew J.|last6=Simpson|first6=Alastair G. B.|date=2018-11-14|title=Hemimastigophora is a novel supra-kingdom-level lineage of eukaryotes|journal=Nature|volume=564|issue=7736|pages=410–414|language=En|doi=10.1038/s41586-018-0708-8|pmid=30429611|bibcode=2018Natur.564..410L|s2cid=205570993|issn=0028-0836}}

Originally, Loukozoa included Anaeromonadea and Jakobea. In 2013, it consisted of three subphyla: Eolouka (Tsukubea and Jakobea), Metamonada and Neolouka (Malawimonas).{{Cite journal|last=Cavalier-Smith|first=Thomas|title=Early evolution of eukaryote feeding modes, cell structural diversity, and classification of the protozoan phyla Loukozoa, Sulcozoa, and Choanozoa|journal=European Journal of Protistology|volume=49|issue=2|pages=115–178|doi=10.1016/j.ejop.2012.06.001|pmid=23085100|year=2013}} In 2018, Cavalier-Smith has removed Eolouka from Loukozoa, placing it instead in Discoba.{{Cite journal|last=Cavalier-Smith|first=Thomas|date=2018-01-01|title=Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences|journal=Protoplasma|language=en|volume=255|issue=1|pages=297–357|doi=10.1007/s00709-017-1147-3|pmid=28875267|pmc=5756292|issn=0033-183X}}

With the root of the Eukaryota likely close to or in Loukozoa or Discoba, these groupings are studied to give unique information on the first eukaryotes.{{Cite journal|last1=Brown|first1=Matthew W|last2=Heiss|first2=Aaron A|last3=Kamikawa|first3=Ryoma|last4=Inagaki|first4=Yuji|last5=Yabuki|first5=Akinori|last6=Tice|first6=Alexander K|last7=Shiratori|first7=Takashi|last8=Ishida|first8=Ken-Ichiro|last9=Hashimoto|first9=Tetsuo|date=2018-01-19|title=Phylogenomics Places Orphan Protistan Lineages in a Novel Eukaryotic Super-Group|journal=Genome Biology and Evolution|language=en|volume=10|issue=2|pages=427–433|doi=10.1093/gbe/evy014|issn=1759-6653|pmc=5793813|pmid=29360967}}