Concise hierarchy

(Kingdom) Animalia - (Phylum) Chordata - (Class) Agnatha

Current position

†unnamed (Subclass)

Ref: M.J. Benton, 2015: 434; Benton, 2015: box 3.1 (p. 48).

Alternative positions

Cephalaspidomorpha (Subclass)	Ref: R.L. Carroll, 1988: 596.
†Cephalaspidomorphi (Subclass) Kiaer & Stensiö, 1920	Ref: B. Grzimek et al., 1974: 45. [inferred rank]
Cephalaspidomorphi (Subclass) Kiaer & Stensiö, 1920
ostracoderms ([unranked])	Ref: A.S. Romer & T.S. Parsons, 1986: App. 1 (p. 620).
†Ostracophori (Class)	Ref: D.S. Jordan, 1923: 86.

Historical positions

†unnamed (Subclass)	Ref: M.J. Benton, 2015: 434, boxes 3.1 (p. 48), 3.7 (p. 74).
†Cephalaspidomorphi (Class) Kiaer & Stensiö, 1920	Ref: J.S. Nelson, 2006: 33. [invalid/synonym] [implicit]
†unnamed (Subclass)	Ref: M.J. Benton, 2005: 390, box 3.1.
Cephalaspidomorpha (Subclass)	Ref: R.L. Carroll, 1988: 596.
Ostracoderms ([unranked])	Ref: A.S. Romer & T.S. Parsons, 1986: App. 1 (p. 620).
†Cephalaspidomorphi (Subclass) Kiaer & Stensiö, 1920	Ref: B. Grzimek et al., 1974: 45. [inferred rank]
†Ostracophori (Class)	Ref: D.S. Jordan, 1923: 86.

Number of Subtaxa

1988	R.L. Carroll: 596	[; †6f]
1923	D.S. Jordan: 86	[; †5f]