Threatened species of Microsporidans
Threatened species of Cnidospora
Myxozoans have always been classified with protistan parasites. Early classifications placed the myxozoans within the phylum Apicomplexa, together in the class Sporozoa and then to the phylum Cnidospora, together with the microsporidians. More recently Microspora was raised to the rank of phylum. This has left Myxozoa to stand alone as a phylum without obvious phylogenetic affinities to other protists. There are serious proposals that myxozoans have their origins in a clade of parasitic cnidarians, and so must be abandoned as a phylum.