The large and heterogenous group of the fungi comprises several phyla. The most primitive are are characterised by the fact that the spores and gametes are motile: they carry a posterior whiplash flagellum. Most species are saprobes, a minority are parasites. Until recently they were understood as a single phylum, but James ao have demonstrated that in fact two phyla should be recognised, separated mainly on details of the flagellar mechanism: Chytridiomycota and Blastocladiomycota
Alexopoulos, Mims & Blackwell (1996a), James, Letcher, Longcore, Mozley-Standridge, Porter, Powell, Griffith & Vilgalys (2006a).