Concise hierarchy

(Kingdom) Animalia - (Phylum) Chordata

Phylogeny

Monophyletic		Ref: J.S. Nelson, 2006: 36.
Holophyletic		Ref: R.L. Carroll, 1988: [16].
Possibly Paraphyletic/Ancestral (para)		Ref: J.S. Nelson et al., 2016: 36.
Paraphyletic/Ancestral (para)		Ref: J.P. Downs, 2020: 676 ("A contemporary view ... regards "placoderms" as a paraphylum") (Johanson, 2002; Brazeau, 2009). [implicit]

First representative

Questionably †Shimenolepis (Genus) Wang, 1991

Ref: J.S. Nelson, 2006: 37.

Current position

Gnathostomata (Superclass) Gegenbaur, 1874

Ref: R. van der Laan, 2018: 26; Chevrinais et al., 2017: fig. 6.

Alternative positions

Gnathostomata (Infraphylum) Gegenbaur, 1874	Ref: M.J. Benton, 2015: 434.
Pisces (Superclass) Linnaeus, 1758	Ref: L.B. Halstead, 1974: 171.
†Placodermiomorphi (Grade)	Ref: J.S. Nelson et al., 2016: 36.
Vertebrata (Subphylum) Cuvier, 1812	Ref: R.L. Carroll, 1988: 596. [implicit]

Historical positions

Gnathostomata (Superclass) Gegenbaur, 1874	Ref: R. van der Laan, 2018: 26.
†Placodermiomorphi (Grade)	Ref: J.S. Nelson et al., 2016: 36.
Gnathostomata (Infraphylum) Gegenbaur, 1874	Ref: M.J. Benton, 2015: 434, box 3.7 (p. 74).
†Placodermiomorphi (Grade)	Ref: J.S. Nelson, 2006: 16, 35-36, fig. (p. 20).
Gnathostomata (Infraphylum) Gegenbaur, 1874	Ref: M.J. Benton, 2005: 390, fig. 3.12.
Chordata ([unranked]) Bateson, 1885	Ref: J.J. Sepkoski Jr., 2002: 299.
Pisces ([unranked])	Ref: 1998
Pisces ([unranked])	Ref: 1995
Gnathostomata ([unranked])	Ref: R.L. Carroll, 1988: 596, fig. 1.3.
Gnathostomata (Superclass) Gegenbaur, 1874	Ref: R.C. van Caenegem et al., 1980: 307.
Vertebrata (Subphylum) Cuvier, 1812	Ref: W.J. Bock, 1982: 830.
Pisces (Superclass) Linnaeus, 1758	Ref: T.I. Storer et al., 1979: 326.
Pisces (Superclass) Linnaeus, 1758	Ref: B. Grzimek, 1973-1975
Pisces (Superclass) Linnaeus, 1758	Ref: L.B. Halstead, 1974: 171.

Number of Subtaxa

2025	Available in Systema Naturae 2000	†13o;65f;163g;64s
1989-present	Systema Naturae 2000: 11 Apr 2024	[; †13o;65f]
2018	R. van der Laan: 32	[; †13o;59f]
2016	J.S. Nelson et al.: 40	[; †7o]
2005	M.J. Benton	[; †6o]
2005	M.J. Benton	[; †6o]
1988	R.L. Carroll: 597	[; †9o;37f]