Concise hierarchy

(Kingdom) Protoctista

Subsequent positions

Archezoa (Subkingdom) Cavalier-Smith, 1983

Ref: T. Cavalier-Smith, 1983b: 1028.

Current position

Protoctista (Kingdom) Hogg, 1860

Ref: L. Margulis & K.V. Schwartz, 1998: 122-123.

Alternative positions

protozoa ([unranked]) Goldfuss, 1818	Ref: R.C. Brusca & G.J. Brusca, 1990
Protozoa (Subkingdom) Goldfuss, 1818	Ref: V. Sprague, 1982: 589.

Historical positions

related to multicellular groups ([unranked])	Ref: 2000: iv, 13. [error]
Amitochondriates ([unranked])	Ref: L. Margulis & K.V. Schwartz, 1998: 122-123.
Protozoa ([unranked]) Goldfuss, 1818	Ref: 1998
Protozoa ([unranked]) Goldfuss, 1818	Ref: 1995
Protista (Kingdom) (Haeckel, 1866)	Ref: R.C. Brusca & G.J. Brusca, 1990: 127. [implicit]
Protoctista (Kingdom) Hogg, 1860	Ref: E.U. Canning, 1990: xiii, 53-72.
Protozoa ([unranked]) Goldfuss, 1818	Ref: R.C. Brusca & G.J. Brusca, 1990: 127. [alternative position]
Protozoa (Subkingdom) Goldfuss, 1818	Ref: V. Sprague, 1982: 589-590.
Protozoa ([unranked]) Goldfuss, 1818	Ref: N.D. Levine et al., 1980

Number of Subtaxa

1989-present	Systema Naturae 2000	2c[3o22f73g]
1990	R.C. Brusca & G.J. Brusca	~800s
1990	E.U. Canning	2c[3o22f73g]
1990	L. Margulis et al.: xiii	2c[3o22f73g]
1982	V. Sprague	2c[3o23f58g]<1000s