Concise hierarchy

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

Current position

Petromyzonti (Class)

Ref: R. van der Laan et al., 2021: (4 Feb 2025); ECoF(4 Feb 2025).

Alternative positions

Agnatha (Class) Cope, 1889	Ref: N. Bailly et al., 2001: 358.
Cephalaspidomorpha (Subclass)	Ref: R.L. Carroll, 1988: 596.
†Cephalaspidomorphi (Class) Kiaer & Stensiö, 1920	Ref: W.N. Eschmeyer & J.D. Fong, 2011: 26.
Petromyzontida (Subclass)	Ref: W.N. Eschmeyer, 1998: 2449. [indirect]
Petromyzontida (Class)	Ref: R. van der Laan, 2018: 15.

Historical positions

Petromyzontida (Class)	Ref: R. van der Laan, 2018: 15.
Petromyzontida (Class)	Ref: J.S. Nelson et al., 2016: 23.
†Cephalaspidomorphi (Class) Kiaer & Stensiö, 1920	Ref: W.N. Eschmeyer, 2004-2016: 24 Jan 2006.
†Cephalaspidomorphi (Class) Kiaer & Stensiö, 1920	Ref: W.N. Eschmeyer & J.D. Fong, 2011: 26.
Petromyzontida (Class)	Ref: J.S. Nelson, 2006: 24-25.
Agnatha (Class) Cope, 1889	Ref: N. Bailly et al., 2001: 358.
Cephalaspidomorpha (Class)	Ref: 2000
†Cephalaspidomorphi (Class) Kiaer & Stensiö, 1920	Ref: 1998
†Cephalaspidomorphi (Class) Kiaer & Stensiö, 1920	Ref: W.N. Eschmeyer, 1998: [2449].
†Cephalaspidomorphi (Class) Kiaer & Stensiö, 1920	Ref: 1995
Cephalaspidomorpha (Subclass)	Ref: R.L. Carroll, 1988: 596.
Cyclostomata (Class) Richards	Ref: T.I. Storer et al., 1979

Number of Subtaxa

2025	Available in Systema Naturae 2000	3f;11g;43s; †2f;4g;4s
1989-present	Systema Naturae 2000: 10 May 2025	[3f;11g; †2f;4g;4s]
2018	R. van der Laan: 15	[3f; †1f]
2016	J.S. Nelson et al.: 26	[3f; †1f]
2004-2016	W.N. Eschmeyer	[1f]
2011	W.N. Eschmeyer & J.D. Fong: 26	1f
1998	W.N. Eschmeyer: 2449	[1f;31ng]
1988	R.L. Carroll: 596	[1f; †1f]
1979	T.I. Storer et al.	~30s