Concise hierarchy

(Kingdom) Animalia - (Phylum) Chordata - (Class) Reptilia - (Order) Ornithischia - (Family) Pachycephalosauridae

Included, by definition, in node-based clade

†Marginocephalia (Clade) Sereno 1986		Ref: P.C. Sereno, 1998: table 4 (p. 62).
†Pachycephalosauridae (Clade) Sternberg 1945		Ref: P.C. Sereno, 1998: table 4 (p. 62).

Included, by definition, in branch-based clade

†Pachycephalosauria (Clade) Maryañska & Osmólska 1974		Ref: P.C. Sereno, 1998: table 4 (p. 62).
†Pachycephalosaurinae (Clade) Sereno 1998		Ref: P.C. Sereno, 1998: table 4 (p. 62).

Excluded, by definition, from branch-based clade

†Ceratopsia (Clade) Marsh 1890		Ref: P.C. Sereno, 1998: table 4 (p. 62).
†Stegoceras (Genus) Lambe, 1902		Ref: P.C. Sereno, 1998: table 4 (p. 62).

Subsequent positions

†Domocephalinae (Subfamily) Sereno, 1986, nom. inval.

Ref: P. Sereno, 1986: 252.

Current position

†Pachycephalosaurini (Tribe) Sullivan, 2003

Ref: R.M. Sullivan, 2006: 357.

Alternative positions

†Domocephalinae (Subfamily) Sereno, 1986, nom. inval.	Ref: P. Sereno, 1986: 252. [new position]
†Pachycephalosauridae (Family) Sternberg, 1945	Ref: D. Lambert & the Diagram Group, 1991(1997): 161.
†Pachycephalosaurinae (Clade) Sereno 1998	Ref: P.C. Sereno, 1998: 68 (fig. 6).

Historical positions

†Pachycephalosaurini (Tribe) Sullivan, 2003	Ref: R.M. Sullivan, 2006: 357.
†Pachycephalosaurinae (Clade) Sereno 1998	Ref: P.C. Sereno, 1998: 68 (fig. 6).
†Domocephalinae (Subfamily) Sereno, 1986, nom. inval.	Ref: P. Sereno, 1986: 252. [new position]

Number of Subtaxa

2025	Available in Systema Naturae 2000	†1s
1989-present	Systema Naturae 2000	†1s
2006	R.M. Sullivan: 357	†1s