Halvaria is a grouping that includes Alveolata and Heterokonta (Stramenopiles).[1]

Analyses in 2007 and 2008 agree that the Stramenopiles and the Alveolata are related, forming a reduced chromalveolate clade. They group together with the Rhizaria (originally one of the six major eukaryote groups) to form a clade dubbed the SAR supergroup.[2][3][4]

A phylogenomic analysis published in 2016 casts doubt on Halvaria, suggesting that Alveolata is the sister group to Rhizaria (the R + A clade) within the SAR supergroup. According to this study, which incorporates new rhizarian sequence data, support for the Halvaria grouping might be an artifact of low taxon sampling as well as long branch attraction.[5]


  1. ^ Cavalier-Smith T (June 2010). "Kingdoms Protozoa and Chromista and the eozoan root of the eukaryotic tree". Biol. Lett. 6 (3): 342–5. doi:10.1098/rsbl.2009.0948. PMC 2880060Freely accessible. PMID 20031978. 
  2. ^ Fabien Burki; Kamran Shalchian-Tabrizi; Marianne Minge; Åsmund Skjæveland; Sergey I. Nikolaev; Kjetill S. Jakobsen; Jan Pawlowski (2007). "Phylogenomics Reshuffles the Eukaryotic Supergroups". PLoS ONE. 2 (8): e790. doi:10.1371/journal.pone.0000790. PMC 1949142Freely accessible. PMID 17726520.  open access publication – free to read
  3. ^ Burki, Fabien; Shalchian-Tabrizi, Kamran & Pawlowski, Jan (2008). "Phylogenomics reveals a new 'megagroup' including most photosynthetic eukaryotes". Biology Letters. 4 (4): 366–369. doi:10.1098/rsbl.2008.0224. PMC 2610160Freely accessible. PMID 18522922. 
  4. ^ Kim, E; Graham, LE (Jul 2008). "EEF2 analysis challenges the monophyly of Archaeplastida and Chromalveolata" (Free full text). PLoS ONE. 3 (7): e2621. doi:10.1371/journal.pone.0002621. PMC 2440802Freely accessible. PMID 18612431.  open access publication – free to read
  5. ^ He, Ding; Sierra, Roberto; Pawlowski, Jan; Baldauf, Sandra L. (2016-08-01). "Reducing long-branch effects in multi-protein data uncovers a close relationship between Alveolata and Rhizaria". Molecular Phylogenetics and Evolution. 101: 1–7. doi:10.1016/j.ympev.2016.04.033. PMID 27132173.