GALLIFORMES AND

Livezey, Bradley C. & Zusi, Richard L., 2007, Higher-order phylogeny of modern birds (Theropoda, Aves: Neornithes) based on comparative anatomy. II. Analysis and discussion, Zoological Journal of the Linnean Society 149 (1), pp. 1-95 : 25

GALLIFORMES AND ANSERIFORMES : LAND AND WATER FOWL

Interordinal relationships: The sister-group relationship between the Galliformes and Anseriformes , reaffirmed here ( Fig. 13 ), was inferred previously by Cracraft (1981, 1988), Cracraft & Mindell (1989), and substantiated thoroughly using morphological ( Dzerzhinsky, 1995; Caspers et al., 1997; Livezey, 1997a, 1998a; Cracraft & Clarke, 2001; Dyke, 2003; Mayr & Clarke, 2003) and molecular data ( Bleiweiss et al., 1994, 1995; Groth & Barrowclough, 1999; Van Tuinen et al., 2000, 2001; Cracraft, 2001; Prychitko & Moore, 2003; Chubb, 2004a; Harrison et al., 2004; Simon et al., 2004; Smith, Li & Zhijian, 2005). However, marginally supported counter-proposals persist ( Ericson, 1996, 1997; Ericson, Parsons & Johansson, 1998; Bourdon, 2005).

Anseriformes : Within the waterfowl ( Anseriformes ), sequential sister-group relationships of the Anhimidae , Anseranatidae and Anatidae , respectively, was previously demonstrated by Livezey (1997a) and confirmed here ( Fig. 13 ). Monophyly of the morphologically diverse and speciose Anatidae , including the true geese ( Anserinae ) and typical ducks ( Anatinae ), is essentially beyond dispute (Livezey, 1986). There exist departures from this arrangement by a minority of workers ( Olson & Feduccia, 1980a; Sraml et al., 1996), but this topology has been substantiated using diverse evidence (Livezey, 1986, 1997a; Quinn, 1992; Donne- Goussé et al., 2002). The historical hypothesis placing the Phoenicopteridae within the Anseriformes ( Table 1) was among the early casualties of formal phylogenetics ( Livezey, 1997a, 1998a).

Galliformes : The pioneering myological works by Hudson, Lanzillotti & Edwards (1959) and Hudson & Lanzillotti (1964) provided early hints concerning relationships of Galliformes , but unfortunately these surveys were not cladistic and followed Peters (1934) in considering unique Opisthocomus as an aberrant galliform. Studies of galliform fossils continue to be phenetic in approach ( Mourer-Chauviré, 2000; Göhlich & Mourer-Chauviré, 2005). Fortunately, this pattern is likely to change with the increasingly common phylogenetic analyses of galliforms ( Dyke, Gulas & Crowe, 2003) and an improved fossil record ( Mayr & Weidig, 2004; Mayr, 2005a).

In the present work, relationships of two families within the Galliformes – Megapodiidae ( Birks & Edwards, 2002) and Cracidae ( Pereira & Baker, 2004; Grau et al., 2005) as mutually monophyletic, sequential sister-groups to all remaining galliforms – agree with placements by other investigators (Prager & Wilson, 1976; Cracraft et al., 2004). Some workers ( Hudson et al., 1966), however, suggested a sister-group relationship between the two families (superfamily Cracoidea ), as opposed to placement as successive sister-groups (paraphyletic) to other galliforms ( Fig. 13 ).

The robust placement of Meleagrididae as sistergroup to the Phasianidae sensu lato in the present work ( Fig. 13 ) opposes inclusion of the family among the enormous complement of other galliforms (reviewed by Sibley & Ahlquist, 1990). The present finding also differs with the indeterminate placement of this distinctive group from most galliforms by Dyke et al. (2003). Dyke et al. (2003: fig. 3) depicted the Megapodiidae and Cracidae as basal, successive sister-groups to the diverse and speciose ‘Phasianoidea’; the latter group included Numida and Acryllium (Numidinae) as members of a polytomous assemblage immediately basal to Meleagris, Agriocharus , Tetraonidae , and a clade comprising 39 taxa of other galliforms inviting taxonomic subdivision. Most of the large-bodied genera of phasianoids (e.g. Gallus , Phasianus ) and the ‘Old World quail and partridges’ were among a large, basal polytomy of the ‘phasianoids’ exclusive of the guineafowl ( Numidinae ). Some of the nodes within this large group, including those resolving Meleagridae and Tetraonidae relative to megapodiid and cracid galliforms, were not sustained by Dyke et al. (2003: fig. 3) in a strict consensus of 1700 MPTs based on 102 characters. Also, the tree inferred here ( Fig. 13 ) departed from those recovered using molecular data (Dimcheff, 2002; Dimcheff, Drovetski & Mindell, 2002).

The vast majority of galliform taxa are members of a morphologically conservative group ( Holman, 1961), many formerly included among the Perdicidae or Odontophoridae (Sibley & Ahlquist, 1990) . These taxa also posed problems of resolution in the present work ( Fig. 13 ), and nodes among these taxa were sufficiently weak as to permit alternative local topologies (i.e. a terminal polytomy). Armstrong, Braun & Kimball (2001) found that mitochondrial and nuclear DNA similarly resolved groupings within a sparse but broad sample of Galliformes . Basal nodes of the latter taxa are broadly consistent with some higher-order topologies (Prager & Wilson, 1976; Helm-Bychowski & Wilson, 1986; Crowe et al., 1992; Kimball et al., 1999; Gutiérrez, Barrowclough & Groth, 2000; Lucchini et al., 2001; Dimcheff et al., 2002; Pereira, Baker & Wajntal, 2002). The single exception among this group (based on included genera) is the strongly supported sister-group relationship between Gallus (Phasianidae) and Numida (Numidinae) . The Numidinae were inferred to be the sister-group of the Phasianidae by Kimball et al. (1999) and Pereira & Baker (2006a).

Figures

Figure 13. Detailed segment of strict consensus tree of all MPTs recovered in present study. Part B. Neornithes: Palaeognathae and Galloanserae. Nodes are labelled above by percentages of bootstrapped replicates in which node was retained (italics), and below by Bremer support indices (bold type).