Galliformes Landfowl

Crown group Galliformes include the Australasian Megapodiidae (megapodes), which are the sister taxon of a clade including the New World Cracidae (guans, chachalacas, and curassows) and the globally distributed Phasianidae (grouse, quails, pheasants, and allies) (Cracraft et al. 2004; Ericson et al. 2006). Although stem group Galliformes may have already existed in the late Cretaceous (see Chap. 4), identification of the fragmentary remains needs to be corroborated with additional specimens. The Paleogene record of galliform birds, however, is quite extensive and provides some insights into the evolutionary history of the group. Most notably, no Paleogene galliform birds have as yet been recorded from Africa, and the fossils indicate a Northern Hemisphere diversification of the taxon (see also Sect. 17.2.1).

Fig. 6.1 Hypothesis on the phylogenetic relationships between Paleogene and extant representatives of the Galloanseres. Selected apomorphies of the nodes: 1 basipterygoid processes ovate and sessile, quadrate with only two mandibular condyles, mandible with long, blade-like retroarticular processes (unknown for Pelagornithidae); 2 palate desmognathous, postorbital process long, with truncate tip, and projecting in rostroventral direction (not comparable in Gastornithidae), zygomatic process reduced; 3 beak duck- or goose-like, with broadly rounded tip; 4 three anterior toes connected with a web; 5 lack of fossa for first metatarsal, distal vascular foramen with plantar opening recessed and situated distal to dorsal opening; 6 sternal extremity of coracoid with large pneumatic opening, sternal extremity of furcula greatly widened; 7 humerus with markedly elongated dorsal tubercle, plantar side of articular surface of tarsometatarsal trochlea for third toe asymmetric, with lateral ridge protruding farther proximally than medial ridge; 8 deltopectoral crest of humerus reduced; 9 capital groove of humerus with transverse ridge; 10 scapular articulation facet of coracoid flat. (After Andors 1992; Mourer-Chauviré 1992a; Murray and Vickers-Rich 2004; Bourdon 2005; Mayr 2006b)

Fig. 6.1 Hypothesis on the phylogenetic relationships between Paleogene and extant representatives of the Galloanseres. Selected apomorphies of the nodes: 1 basipterygoid processes ovate and sessile, quadrate with only two mandibular condyles, mandible with long, blade-like retroarticular processes (unknown for Pelagornithidae); 2 palate desmognathous, postorbital process long, with truncate tip, and projecting in rostroventral direction (not comparable in Gastornithidae), zygomatic process reduced; 3 beak duck- or goose-like, with broadly rounded tip; 4 three anterior toes connected with a web; 5 lack of fossa for first metatarsal, distal vascular foramen with plantar opening recessed and situated distal to dorsal opening; 6 sternal extremity of coracoid with large pneumatic opening, sternal extremity of furcula greatly widened; 7 humerus with markedly elongated dorsal tubercle, plantar side of articular surface of tarsometatarsal trochlea for third toe asymmetric, with lateral ridge protruding farther proximally than medial ridge; 8 deltopectoral crest of humerus reduced; 9 capital groove of humerus with transverse ridge; 10 scapular articulation facet of coracoid flat. (After Andors 1992; Mourer-Chauviré 1992a; Murray and Vickers-Rich 2004; Bourdon 2005; Mayr 2006b)

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