<P> In cladistic systems, there are no equivalents to the taxa Protista or Protoctista, both terms referring to a paraphyletic group which spans the entire eukaryotic tree of life . In cladistic classification, the contents of Protista are distributed among various supergroups (SAR, Archaeplastida, Excavata, Opisthokonta, etc .) and "Protista",' ' Protoctista' ' and "Protozoa" are considered obsolete . However, the term "protist" continues to be used informally as a catch - all term for eukaryotic microorganisms . For example, the phrase "protist pathogen" may be used to denote any disease - causing microbe which is not bacteria, virus, viroid or metazoa . </P> <P> The term protista was first used by Ernst Haeckel in 1866 . Protists were traditionally subdivided into several groups based on similarities to the "higher" kingdoms such as: </P> <P> Protozoa the unicellular "animal - like" (heterotrophic / parasitic) protozoa which was further sub-divided based on motility such as (flagellated) Flagellata, (ciliated) Ciliophora, (phagocytic) amoeba and spore - forming Sporozoans </P> <P> Protophyta the "plant - like" (autotrophic) protophyta (mostly unicellular algae) </P>

Example of an organism in the protista kingdom