Table 3.

Alternative topological inferences and minimal differences in tree length (additional steps) relative to placements in MPTs (Figs 11–17), conditional on other topological alterations being prohibited (optimizations of characters thereon permitted). Higher-order taxa correspond to classification proposed in Appendix 1

Taxon	Alternative hypothesis*	Δ length	References
Palaeognathae	∪ Galloanseromorphae	54	Sibley & Ahlquist (1990)
Ratitae (global)†	Δ topology	31	Cracraft (1974a)
Ratitae (local)†	Δ topology	63	Cracraft (1974a)
	Δ topology‡	17	Cooper et al. (2001)
	Δ topology‡	13	Haddrath & Baker (2001)
Galloanserimorphae	Polyphyly§	[19]	Bourdon et al. (2005)
Galliformes	Polyphyly	90	Dyke et al. (2003)
Megapodiidae	∪ Cracidae	10	Dyke et al. (2003)
Meleagrididae	∪ Phasianidae	20	Dyke et al. (2003)
Anseriformes	Δ familial topology	54	Olson & Feduccia (1980a); Livezey (1997a)
Anhimae	∪∨⊂ Galliformes	41	Olson & Feduccia (1980a); Livezey (1997a)
Gaviomorphae	∪ Charadriomorphae	72	Storer (1956); Olson (1985)
Podicipediformes	∪ Phoenicopteridae	146	Mayr & Clarke (2003); Mayr (2004a)
	∪ Charadriomorphae	54	Storer (1956)
	∪ Eurypygidae	182	Zusi & Storer (1969)
	∪ Ralliformes	159	Olson (1985); Houde (1994)
Pelecaniformes	Δ topology	344	Kennedy & Spencer (2004: fig. 1B)
Sulae	Δ topology	125	Kennedy et al. (2005: fig. 8)
Balaenicepitidae	¬∪ Pelecaniformes	30	Cracraft (1985); Mayr (2003a)
Scopidae	∪∨⊂ Pelecaniformes	23	Mayr (2003a)
Threskiornithidae	∪∨⊂ Charadriiformes	174	Olson (1978)
Ardeidae	⊂ (Turnices ∪ Eurypygae)	75	Olson (1978)
Phoenicopteridae	∪ Anseriformes	107	Feduccia (1976, 1977b); Hagey et al. (1990)
	∪ Cladorhynchini	154	Olson & Feduccia (1980b)
Gruiformes (traditional)	Monophyly¶	11	Livezey (1998b)
Charadriiformes	Δ topology	60	Strauch (1978) fideChu (1995: fig. 1)
	Δ topology	106	Sibley & Ahlquist (1990) fidePaton et al. (2003)
	Δ topology	82	Chu (1995: fig. 8), excluding Ibidorhyncha
Mesitornithidae	∪ Cuculiformes	107	Mayr & Ericson (2004)
Strigiformes	∪ Caprimulgiformes	43	Hoff (1966)
Cathartidae	∪∨⊂ Ciconiiformes	112	Ligon (1967); Rea (1983); Avise et al. (1994a)
Opisthocomidae	∪∨⊂ Galliformes	120	Hudson et al. (1959); Hudson & Lanzillotti (1964)
	∪ Cuculiformes**	22	Avise et al. (1994b); Hughes & Baker (1999)
Caprimulgiformes	Polyphyly	31	Mayr (2002a, b)
	∪ Cypselomorphae	42	Mayr (2002a, 2003c, 2004d, 2005f, g)
Aegothelidae	∪ Apodiformes	31	Mayr (2002a, 2003c, 2004d, 2005f, g)
Steatornithidae	∪ Trogoniformes	102	Mayr (2003b)
Hemiprocnidae	∪ Apodidae, monophyly	5	Sibley & Ahlquist (1990: fig. 361)
Apodidae	∪ Passeri (Hirundinidae)	193	Shufeldt (1889b); Van Tuinen (2002)
Galbulae	∪∨⊂ Coraciiformes	20	Olson (1983a)
Coraciiformes	Δ topology, ∈ Trogoniformes	199	Lowe (1946); Maurer & Raikow (1981)
Coracii	Δ topology	64	Cracraft (1971b)
Menura	∪∨⊂ Passeri	11	Irestedt et al. (2001); Barker et al. (2002)

^*Set-symbolism coopted for concise statement of phylogenetic hypotheses, as follows: ∪, sister-group (disjoint) union; ⊂, included as subclade; ∈, included as a member taxon; ∨, or; Δ, change in; ¬, not (negation of predicate argument).

^†Local optima for Aepyornithiformes and Dinornithiformes (as bi-ordinal sister-group to ratites exclusive of Apterygiformes) and global optima (former as sister-group to Struthionidae and Rheidae, latter as sister-group to ratites exclusive of Apterygiformes).

^‡Comparisons excluded effects due to differences in outgroup taxa, as well as tentatively placed Aepyornithiformes.

^§Doubtful comparability given differences in taxonomic samples between studies.

^¶Corresponds to that proposed by Livezey (1998b), exclusive of Pedionomidae and fossil gruiforms (Cracraft 1969, 1971a, 1973a).

^**Alternative hypothesis compared sister-grouping with Cuculiformes exclusive of Musophagidae.