micronuclearia micronuclearia micronuclearia is a genus of free-living protozoa. while originally thought to be a nucleariid, as reflected in the name, it is now inferred to be a member of the taxon rigifilida, and to belong to the 'crums' assemblage (whereas nucleariids are opisthokonts). micronuclearia scientific classification domain: eukaryota clade: opimoda clade: crums order: rigifilida genus: micronucleariamikrjukov and mylnikov, 2001 species micronuclearia podoventralis mikrjukov & mylnikov, 2001 the type species is micronuclearia podoventralis.