Temporal range: 736–0 Ma
Burki et al., 2007
SAR or Harosa (informally the SAR supergroup) is a clade that includes stramenopiles (heterokonts), alveolates, and Rhizaria. The name is an acronym derived from the first letters of each of these clades; it has been alternatively spelled "RAS".
The term "Harosa" (at the subkingdom level) has also been used for this grouping by Cavalier-Smith (2010). Adl et al. (2012) formalized the SAR supergroup as the node-based taxon Sar. They defined it as:
Sar: the least inclusive clade containing Bigelowiella natans Moestrup & Sengco 2001 (Rhizaria), Tetrahymena thermophila Nanney & McCoy 1976 (Alveolata), and Thalassiosira pseudonana Cleve 1873 (Stramenopiles). This is a node-based definition in which all of the specifiers are extant.
Note that as a formal taxon, "Sar" has only its first letter capitalized, while the earlier abbreviation, SAR, retains all uppercase letters. Both names refer to the same group of organisms, unless further taxonomic revisions deem otherwise. Members of the SAR supergroup were once included under the separate supergroups Chromalveolata (Chromista and Alveolata) and Rhizaria, until phylogenetic studies confirmed that stramenopiles and alveolates diverged with Rhizaria. This apparently excluded haptophytes and cryptomonads, leading Okamoto et al. (2009) to propose the clade Hacrobia to accommodate them.
Based on a compilation of the following works.