Concise hierarchy

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

Original entries

Questionably †Apatotheria (Order) Scott & Jepsen, 1936
Questionably Dermoptera (Order) Dobson, 1883
Questionably †Desmostylia (Order) Reinhart, 1953
Questionably †Embrithopoda (Order) Andrews, 1906
Questionably †Mesonychia (Order) Matthew, 1937
Questionably †Pantodonta (Order) Cope, 1873
Questionably †Pantolesta (Order) McKenna, 1975
Questionably Pholidota (Order) Weber, 1904
Questionably Sirenia (Order) Gill, 1872
Questionably †Taeniodonta (Order) Cope, 1876
Questionably †Tillodontia (Order) Marsh, 1875

Subsequent entries

Cetacea (Order) Brisson, 1762
Hyracoidea (Order) Huxley, 1869
Proboscidea (Order) Owen, 1859

Current position

Theria (Subclass) Parker & Haswell, 1897

Ref: C.J. Burgin et al., 2020: table 2 (p. 26).

Alternative positions

Boreosphenida (Subclass) Luo, Cifelli & Kielan-Jaworowska, 2001	Ref: K.D. Rose, 2006: table 1.2.
Theria (Clade) Parker & Haswell 1897 [McKenna 1975]	Ref: C.J. Burgin et al., 2020: table 2 (p. 26). [implicit]

Historical positions

Theria (Subclass) Parker & Haswell, 1897	Ref: C.J. Burgin et al., 2020: table 2 (p. 26).
Mammalia (Class) Linnaeus, 1758	Ref: S. Bi et al., 2018: 390. [rough position]
Theria (Subclass) Parker & Haswell, 1897	Ref: C. Groves & D. Happold, 2013: 102.
Boreosphenida (Subclass) Luo, Cifelli & Kielan-Jaworowska, 2001	Ref: K.D. Rose, 2006: tables 1.2, 4.1, fig. 4.2.
Boreosphenida (Subclass) Luo, Cifelli & Kielan-Jaworowska, 2001	Ref: Z. Kielan-Jaworowska et al., 2004 (alt.): table 1.1 (p. 15).
Boreosphenida (Subclass) Luo, Cifelli & Kielan-Jaworowska, 2001	Ref: Z. Kielan-Jaworowska et al., 2004: tables 1.2 (p. [17]), 13.1 (p. [494]). [new position]
Theria of Metatherian-Eutherian grade ([unranked])	Ref: R.L. Carroll, 1988: 629, table A-1 (p. 629).
Theria (Subclass) Parker & Haswell, 1897	Ref: A.S. Romer & T.S. Parsons, 1986
Theria (Subclass) Parker & Haswell, 1897	Ref: A.F. DeBlase, 1982: 1021-1022.
Theria (Subclass) Parker & Haswell, 1897	Ref: L. Margulis & K.V. Schwartz, 1982: 239.
Theria (Subclass) Parker & Haswell, 1897	Ref: T.I. Storer et al., 1979
Theria (Subclass) Parker & Haswell, 1897	Ref: L.B. Halstead, 1974: 172.
Theria (Subclass) Parker & Haswell, 1897	Ref: G.G. Simpson, 1945

Number of Subtaxa

2025	Available in Systema Naturae 2000	19o;144f;1112g;4794s;4140ss;302v; ‡10f;49g;99s;31ss;1v; †25o;249f;3920g;1335s;64ss;1v
1989-present	Systema Naturae 2000	[19o;115f; ‡1o;9f;49g; †26o;243f;4015g]
2020	C.J. Burgin et al.: table 2 (p. 27)	[19o;139f; ‡5f]
2013	C. Groves & D. Happold: 102	21o
1988	R.L. Carroll: 648	[18o;102f; ‡4f; †18o;173f]
1982	A.F. DeBlase: 1021	17o;[114f]
1982	A.F. DeBlase: 1021	17o;[114f]
1974	L.B. Halstead: 172	[12o]
1945	G.G. Simpson:	[16o; †10o]