Extraordinary cranial specialization in a new genus of extinct duck (Aves: Anseriformes) from Kauai, Hawaiian Islands Author Iwaniuk, Andrew N. Author Olson, Storrs L. Author James, Helen F. text Zootaxa 2009 2296 47 67 journal article 10.5281/zenodo.191607 80f99135-d8a1-4ac5-8c0c-7a32f6c093a9 1175-5326 191607 Genus Talpanas new genus (Olson & James) Type species. Talpanas lippa Olson and James , new species , by original designation. Included species. Type species only. Distribution. Kauai, Hawaiian Islands. Etymology. L. talpa (f.) a mole, plus anas (f.), a duck, in allusion to the greatly reduced size of the eyes. The gender is feminine. Among mammals, the closest analog of the new genus of duck in the appearance of the cranium, as well as in the similarity in trigeminal enlargement ( Home 1802 ), is the platypus ( Ornithorhynchus anatinus ), an alternate vernacular of which among Australian colonists was "duck-mole." The reduced eyes and poor vision of moles ( Talpidae ) are well known. Diagnosis. Anatidae with braincase very broad and dorsoventrally compressed, with greatly reduced orbits. Maxillo-mandibular foramen and foramen n. olfactorii greatly enlarged relative to all other waterfowl. The orbit is greatly reduced in size and laterally displaced, allowing the nasal cavity to extend caudally and directly abut the brain cavity. There is consequently no mesethmoidal sulcus for the olfactory nerves, whereas in other anatids the orbit separates the olfactory and brain cavities, requiring long olfactory nerves to traverse the orbit. The nasal gland depressions are seated against extensive flat surfaces of the frontal that face laterad, whereas in most other Anatidae these depressions face dorsad. TABLE 1. Sample sizes (n) and mean linear dimensions (in mm) of the skulls of the 145 species included in our analyses. Details regarding the landmarks used for all eight measurements are provided in the text. Data for Talpanas lippa are shown in bold.

Species Aix galericulata	n 6	Skull length 43.8	Interorbital width 8.8	Skull depth 23.9	Naso-frontal hinge width 9.8	Supra-orbital process width 17.0	Lacrimal Post-orbital width process width 19.6 24.0	Braincase width 22.6
Aix sponsa	4	45.6	8.1	25.3	12.0	18.0	20.9 25.5	23.3
Alopochen aegyptiacus	4	58.9	12.8	28.9	15.6	23.9	27.7 33.5	29.7
Amazonetta brasiliensis Anas acuta Anas americana	4 6 6	43.8 52.6 47.5	8.2 9.3 6.4	23.0 25.2 23.8	10.4 11.5 10.1	15.0 16.5 13.8	19.0 24.1 20.0 26.6 18.5 24.0	20.9 24.4 22.1
Anas aucklandica Anas bahamensis Anas capensis	1 4 1	46.8 47.4 44.1	6.0 7.7 5.6	22.1 23.2 21.3	9.6 11.6 9.8	15.2 16.0 16.1	17.4 23.3 18.8 24.1 18.8 22.9	22.8 22.6 21.1
Anas castanea	4	47.5	8.4	24.1	10.6	16.7	18.0 24.2	22.1
Anas clypeata Anas crecca Anas cyanoptera	8 8 5	51.6 42.6 44.6	6.9 12.0 6.9	22.6 21.7 21.8	10.5 8.9 9.7	13.8 13.1 11.9	18.8 23.3 16.2 21.5 16.4 21.2	20.9 19.4 19.1
Anas discors Anas erythrorhyncha Anas falcata Anas flavirostris	6 4 4 4	43.9 46.8 50.6 43.7	6.5 8.5 7.0 6.6	21.5 23.1 24.8 22.4	9.4 11.3 11.8 9.2	12.3 15.2 16.8 14.9	16.4 21.6 18.9 24.7 21.0 26.1 18.1 22.7	19.2 22.6 23.4 20.4
Anas formosa Anas georgica Anas gracilis	3 3 3	45.6 48.3 47.3	7.5 9.4 7.0	22.7 24.5 22.0	11.0 11.2 9.5	13.9 15.6 14.2	19.6 24.2 19.7 26.1 16.9 23.0	21.6 22.8 21.3
Anas hottentota	4	40.6	6.1	20.6	8.5	12.7	16.4 20.3	19.1
Anas laysanensis	4	39.0	8.2	21.9	8.9	11.9	13.5 22.0	19.7
Anas luzonica Anas melleri	3 1	51.6 55.6	9.0 8.2	25.3 25.4	12.6 13.1	16.1 13.5	21.6 27.3 22.9 27.8	24.4 24.5
Anas penelope	4	46.0	5.8	22.7	10.4	14.9	18.3 24.3	22.2
Anas platalea Anas platyrhynchos	3 7	49.3 56.5	6.9 9.7	22.3 26.8	12.1 13.3	15.9 16.2	21.4 24.2 22.7 28.6	20.7 25.6
Anas poecilorhyncha	4	55.8	9.8	26.5	13.4	16.8	23.6 29.1	23.1

continued next page continued next page TABLE 1. (continued)

Species	n	Skull length	Interorbital width	Skull depth	Naso-frontal hinge width	Supra-orbital process width	Lacrimal Post-orbital width process width	Braincase width
Anas querquedula	3	42.0	5.7	20.9	9.4	11.8	16.5 21.6	19.1
Anas rhynchotis Anas rubripes	2 4	50.9 56.5	5.8 7.8	22.4 27.2	10.6 13.1	15.0 16.7	20.0 23.2 23.2 28.7	20.2 26.4
Anas sibilatrix	4	48.1	7.2	22.9	10.3	14.9	17.3 25.2	21.6
Anas smithii Anas sparsa	4 2	50.1 52.0	6.8 9.4	22.6 24.9	11.2 11.5	16.2 15.2	18.9 23.8 20.2 27.7	20.6 24.5
Anas specularis	1	56.3	9.0	26.8	14.5	18.2	23.3 28.7	24.2
Anas strepera	5	49.6	6.8	22.9	10.3	15.4	18.0 24.9	22.5
Anas superciliosa Anas undulata	4 2	49.3 52.6	8.5 9.1	24.1 27.0	11.8 14.2	14.2 16.9	20.8 25.3 22.8 27.6	22.8 24.5
Anas versicolor	4	42.7	6.8	22.4	9.1	14.3	16.0 22.5	20.2
Anas wyvilliana	4	45.7	8.6	23.8	11.1	13.9	19.0 24.4	23.1
Anser albifrons Anser anser Anser caerulescens	6 4 4	53.5 62.9 53.9	13.2 17.7 14.7	31.9 38.2 33.6	18.5 26.7 19.8	21.4 31.7 22.9	25.4 35.0 35.9 43.8 27.5 36.3	30.8 35.6 32.2
Anser canagicus Anser cygnoides Anser fabalis	4 2 6	50.5 72.6 53.8	9.5 20.5 14.0	31.3 35.5 33.5	17.9 25.9 18.5	21.9 29.2 23.5	25.7 34.6 31.6 42.3 25.5 34.3	31.6 34.7 31.8
Anser indicus	2	51.9	11.3	30.3	16.5	22.2	26.1 32.0	30.2
Anser rossii Anseranas semipalmata Aythya affinis	5 3 5	45.9 56.6 46.4	11.7 14.2 6.9	28.7 33.2 23.7	15.4 17.2 10.8	17.9 23.9 15.7	22.1 29.0 24.8 37.9 17.7 26.3	28.0 32.4 23.8
Aythya americana Aythya australis Aythya baeri Aythya collaris	4 3 1 4	51.2 51.3 48.9 47.9	6.2 9.9 9.5 9.2	25.0 24.5 23.8 24.3	13.1 13.8 13.5 13.5	15.8 15.9 16.0 16.1	19.0 28.8 20.4 28.0 20.4 27.2 19.8 28.4	25.2 24.2 24.6 25.1
Aythya ferina Aythya fuligula Aythya innotata	4 4 1	50.8 45.0 49.4	8.1 8.1 9.3	24.5 22.8 24.3	12.2 11.2 12.3	14.7 14.3 15.3	18.5 28.2 16.3 25.8 19.1 28.1	25.3 23.2 25.2
Aythya marila	4	50.5	7.4	24.3	13.0	16.7	21.0 29.6	25.2
Aythya novaeseelandiae	1	47.1	7.1	22.0	10.3	13.0	16.0 24.5	22.5
Aythya nyroca Aythya valisineria	3 4	43.4 57.9	8.7 8.5	23.3 26.2	11.9 12.5	13.4 15.2	17.1 25.0 18.9 29.4	22.8 27.0
Biziura lobata	2	49.7	7.3	25.5	13.2	15.1	24.0 29.0	26.6
Branta bernicla Branta canadensis minima Branta canadensis moffitti Branta canadensis taverneri	4 4 3 3	48.8 44.0 60.7 49.7	8.5 8.0 13.9 11.0	26.0 26.3 34.3 29.9	14.6 12.2 19.7 14.6	22.2 16.4 24.9 20.6	23.6 30.4 17.5 26.9 28.7 34.6 21.9 30.2	27.5 25.4 33.5 30.1
Branta leucopsis Branta ruficollis	1 3	46.8 43.3	9.6 10.0	28.4 26.5	12.7 12.7	21.2 17.8	19.8 29.9 22.8 26.6	27.8 24.2
Branta sandvicensis	3	50.2	12.7	29.1	16.8	20.5	23.8 31.6	29.4

TABLE 1. (continued)

Species n	Skull length	Interorbital width	Skull depth	Naso-frontal hinge width	Supra-orbital process width	Lacrimal Post-orbital width process width	Braincase width
Bucephala albeola 4	41.2	4.6	22.1	8.0	11.3	17.8 23.1	22.0
Bucephala clangula 4	52.9	12.2	29.1	14.1	17.2	23.3 29.9	26.7
Bucephala islandica 3	54.7	11.1	28.9	14.0	18.2	24.6 30.7	27.8
Cairina moschata 2	64.5	14.3	32.9	18.0	25.7	31.6 38.0	30.8
Cairina scutulata 4	62.1	14.7	31.6	16.6	23.7	27.8 35.7	30.5
Calonetta leucophrys 2	40.1	7.3	21.2	9.5	14.5	18.0 21.2	20.0
Cereopsis 4 novaehollandiae	57.0	10.3	31.7	18.8	26.9	28.7 35.3	31.2
Chenonetta jubata 3	43.9	9.3	24.4	10.9	16.9	18.3 24.9	22.3
Chloephaga hybrida 4	57.6	10.2	29.6	14.1	25.3	28.5 32.0	28.6
Chloephaga 3 melanoptera	59.9	15.4	30.0	15.9	26.1	28.7 34.9	29.5
Chloephaga picta 4	60.1	14.7	30.9	15.5	26.5	29.3 33.8	29.1
Chloephaga 3 poliocephala	52.3	11.7	26.6	12.7	23.0	23.2 29.0	26.3
Chloephaga rubidiceps 1	50.9	7.3	26.4	12.2	28.1	27.4
Clangula hyemalis 7	47.8	5.6	22.3	9.3	13.7	18.6 27.1	24.9
Coscoroba coscoroba 4	68.3	11.9	28.4	17.1	25.4	28.5 35.6	32.9
Cyanochen cyanopterus 4	53.7	11.9	28.4	13.6	20.8	20.8 30.2	27.5
Cygnus atratus 4	70.0	13.8	33.9	22.7	27.9	30.9 40.6	36.7
Cygnus buccinator 5	90.3	20.1	42.1	24.6	32.5	39.9 48.8	44.6
Cygnus columbianus 4	81.5	16.5	37.5	22.2	29.5	35.6 44.2	40.1
Cygnus cygnus 1	88.0	18.3	39.3	23.9	30.6	36.9 46.0	41.6
Cygnus melancoryphus 4	66.1	12.2	30.9	19.4	24.8	30.4 37.6	33.6
Cygnus olor 4	85.2	17.1	34.6	23.4	34.1	41.0 48.7	42.0
Dendrocygna arborea 4	48.9	10.4	25.9	16.2	18.7	25.4 29.0	25.5
Dendrocygna arcuata 4	44.2	9.4	23.0	14.0	15.7	22.4 26.2	23.5
Dendrocygna 4 autumnalis	47.7	11.4	24.4	15.6	17.0	23.3 27.4	24.2
Dendrocygna bicolor 3	47.4	10.3	24.0	14.3	15.3	22.7 26.3	23.4
Dendrocygna eytoni 4	43.9	12.5	25.4	14.4	20.1	24.0 26.8	24.5
Dendrocygna guttata 3	44.4	9.5	24.4	13.1	16.3	20.5 26.2	23.4
Dendrocygna viduata 4	46.2	11.3	24.5	15.1	17.2	23.0 26.1	24.0
Heteronetta atricapilla 2	44.7	7.1	20.6	11.2	13.1	17.7 24.1	19.7
Histrionicus histrionicus 5	45.7	5.9	23.9	8.7	13.0	17.4 26.1	24.6
Hymenolaimus 1 malacorhynchus	48.8	8.7	23.0	9.7	12.9	17.6 26.1	25.8
Lophodytes cucullatus 4	41.4	7.2	21.4	9.9	12.0	17.7 24.8	24.1
Lophonetta 4 specularoides	51.9	6.1	24.4	10.8	16.5	20.4 26.9	23.4
Malacorhynchus 1 membranaceus	41.0	5.6	20.5	8.3	13.6	17.4 19.9	18.9
Marmaronetta 4 angustirostris	45.7	7.8	21.8	11.6	16.2	19.2 24.3	21.6
Melanitta fusca 4	57.8	9.7	27.7	16.7	20.2	28.8 33.7	30.2

continued next page TABLE 1. (continued)

Species n	Skull length	Interorbital width	Skull depth	Naso-frontal hinge width	Supra-orbital process width	Lacrimal Post-orbital width process width	Braincase width
Melanitta nigra 4	50.4	7.4	25.7	11.2	18.0	21.2 29.1	26.3
Melanitta perspicillata 7 Mergellus albellus 2	53.2 40.4	7.4 6.2	24.9 21.0	12.1 9.8	16.8 8.1	21.0 29.5 25.2	26.6 24.4
Mergus merganser 5	47.6	9.6	20.9	13.4	16.2	20.5 32.4	29.1
Mergus octosetaceus 1 Mergus serrator 6	42.3 42.8	7.5 5.8	18.4 20.0	7.5 10.5	14.2 13.0	17.7 29.6 18.0 28.2	26.8 26.5
Mergus squamatus 1	45.8	8.7	19.7	12.3	15.4	18.9 29.8	27.8
Neochen jubatus 4	51.1	14.0	26.8	13.7	23.0	25.4 30.2	27.3
Netta erythrophthalma 3 Netta peposaca 4	46.1 50.7	8.2 10.1	24.9 25.6	11.9 14.3	14.0 18.1	18.3 27.3 20.3 29.5	24.9 25.2
Netta rufina 4	50.0	7.5	23.6	13.5	16.6	19.6 28.6	24.7
Nettapus auritus 4	33.5	6.1	20.3	9.1	13.0	15.6 20.4	18.7
Nettapus 4 coromandelianus Nettapus pulchellus 1 Oxyura australis 1 Oxyura dominica 4	33.3 33.9 44.8 39.1	6.1 6.4 8.2 6.4	19.3 19.4 22.8 20.7	12.3 9.8 13.7 12.6	12.8 14.4 15.6 14.2	14.3 19.0 15.2 20.2 22.3 27.6 18.9 23.9	17.9 17.9 23.9 21.1
Oxyura jamaicensis 5 Oxyura maccoa 2 Oxyura vittata 2	43.7 47.1 43.4	6.5 9.3 7.6	22.0 23.4 22.9	11.7 15.5 12.7	12.9 17.8 14.1	17.2 24.8 22.3 26.7 19.3 26.2	22.0 24.0 23.1
Plectropterus gambensis 4	74.4	20.9	39.0	23.3	32.6	35.8 43.6	35.2
Polysticta stelleri 5	50.0	6.8	23.2	9.6	15.6	14.8 26.2	25.4
Pteronetta hartlaubi 2 Sarkidiornis melanotos 4	52.3 58.1	10.9 13.7	27.9 29.1	13.7 17.2	19.4 24.1	22.2 29.8 26.4 31.7	25.9 27.9
Somateria fischeri 3	58.3	7.1	28.3	12.2	18.4	22.3 31.3	29.7
Somateria mollissima 5 Somateria spectabilis 4	68.1 58.6	7.6 8.1	28.1 26.5	12.9 12.6	20.7 19.4	24.3 35.0 20.2 30.2	32.0 27.9
Stictonetta naevosa 4	53.7	11.0	23.7	16.3	20.4	26.3 29.3	23.8
Tachyeres brachypterus 3	72.2	10.9	33.2	19.1	28.7	29.2 42.2	36.0
Tachyeres leucocephalus 1 Tachyeres patachonicus 2	68.4 67.0	8.5 9.8	31.7 31.7	17.0 17.7	22.3 24.5	25.8 38.5 28.2 38.9	32.6 31.3
Tachyeres pteneres 3	75.4	11.2	34.1	20.1	30.5	31.5 42.4	36.0
Tadorna cana 4	54.0	10.8	25.7	11.8	18.6	23.8 28.3	26.4
Tadorna ferruginea 4 Tadorna radjah 4 Tadorna tadorna 4	53.4 48.9 52.6	10.1 9.1 7.0	24.7 25.2 23.8	12.6 12.2 12.2	18.7 18.6 17.5	24.1 29.3 23.0 27.6 21.8 28.7	26.1 25.0 25.4
Tadorna tadornoides 1 Tadorna variegata 2 Thalassornis leuconotus 2	56.0 56.2 43.3	10.2 10.2 8.0	24.8 25.3 23.9	12.6 12.0 16.1	19.0 18.8 15.2	23.5 29.2 23.3 30.2 19.2 28.3	26.4 27.0 24.3
Talpanas lippa 1	36.5	10.5	19.9	12.5	12.7	15.4 29.7	26.7

TABLE 2. Samples sizes (n), mean cross-sectional areas of the trigeminal foramen (nV), optic foramen (nII) and foramen magnum and angle of the palatines for all 150 species measured. Extinct species are underlined and Talpanas lippa is shown in bold.

Species	n nV foramen (mm2)	nII foramen (mm2)	Foramen magnum (mm2)	Palatine angle (°)
Aix galericulata Aix sponsa	4 2.4 4 1.5	13.1 14.1	27.7 28.8	19.1 23.9
Alopochen aegyptiacus Amazonetta brasiliensis Anas acuta Anas americana Anas aucklandica Anas bahamensis Anas capensis Anas castanea	4 3.8 4 2.5 6 4.7 5 3.7 1 5.0 4 3.8 1 3.8 4 3.8	16.6 9.4 8.8 9.4 5.7 7.6 6.8 7.6	48.0 28.8 35.7 30.9 39.4 33.0 34.6 30.0	23.9 24.2 23.5 20.4 21.3 24.8 25.3 22.4
Anas clypeata Anas crecca	8 4.9 8 4.2	6.9 6.9	32.6 24.6	19.7 23.1
Anas cyanoptera Anas discors Anas erythrorhyncha Anas falcata Anas flavirostris Anas formosa Anas georgica Anas gracilis	5 3.9 6 3.2 4 3.3 4 3.7 4 4.4 3 3.5 4 4.4 3 4.8	6.1 5.8 7.9 9.7 7.2 7.5 6.5 7.6	25.5 23.0 33.3 31.7 26.1 27.5 33.3 30.2	23.1 25.3 21.2 19.2 21.0 23.6 18.8 23.1
Anas hottentota Anas laysanensis	4 3.6 3 3.5	5.4 6.3	23.9 30.3	27.7 21.6
Anas luzonica Anas melleri Anas penelope Anas platalea Anas platyrhynchos Anas poecilorhyncha Anas querquedula Anas rhynchotis	3 4.2 1 5.2 4 2.8 2 2.6 7 5.7 3 5.0 3 5.0 2 3.6	11.2 11.6 8.3 5.7 10.4 11.4 6.0 6.9	35.3 43.1 30.1 29.7 44.0 45.3 23.7 26.1	27.4 27.9 22.9 19.5 23.2 22.8 22.0 -
Anas rubripes Anas sibilatrix	5 5.5 3 3.1	10.2 8.0	42.9 32.6	27.1 22.2
Anas smithii Anas sparsa Anas specularis Anas strepera Anas superciliosa Anas undulata	4 3.2 2 4.1 1 5.1 7 3.5 4 4.1 2 4.0	7.4 9.7 11.6 8.4 11.2 8.8	31.4 34.4 53.4 30.7 38.1 40.5	18.0 18.4 23.5 22.2 21.5 26.1

continued next page Species n nV foramen nII foramen Foramen magnum Palatine angle TABLE 2. (continued) (mm2) (mm2) (mm2) (°) Anas versicolor 4 4.5 6.8 25.6 23.3 Anas wyvilliana 4 4.5 7.9 31.6 23.2 Anser albifrons 4 3.6 9.2 59.1 22.4 Anser anser 4 4.7 12.4 65.5 29.0 Anser caerulescens 4 4.7 10.2 53.7 26.0 Anser canagicus 4 4.9 10.2 53.3 22.0 Anser cygnoides 2 8.1 10.6 74.0 26.5 Anser fabalis 6 3.9 11.8 53.4 26.4 Anser indicus 2 3.7 12.1 59.1 24.7 Anser rossii 4 3.0 8.9 39.9 22.1 Anseranas semipalmata 3 6.2 9.7 45.6 26.0 Aythya affinis 5 4.0 7.4 32.2 27.2 Aythya americana 4 4.1 8.5 43.9 27.4 Aythya australis 2 2.8 8.8 45.0 25.2 Aythya baeri 1 3.0 10.2 38.7 26.9 Aythya collaris 4 3.3 8.9 36.5 26.1 Aythya ferina 4 5.4 8.5 47.5 28.4 Aythya fuligula 4 3.2 8.3 35.4 25.5 Aythya innotata 1 2.6 9.8 35.0 27.7 Aythya marila 4 4.3 7.3 41.4 26.3 Aythya novaeseelandiae 1 4.1 9.5 26.9 23.6 Aythya nyroca 3 4.0 9.2 31.4 26.9 Aythya valisineria 4 5.1 10.3 49.5 26.9 Biziura lobata 2 6.0 12.9 49.5 34.5 Branta bernicla 4 2.5 8.8 45.5 23.1 Branta canadensis minima 4 1.9 9.1 44.8 28.9 Branta canadensis moffitti 3 4.9 16.2 64.5 23.4 Branta canadensis taverneri 3 4.9 13.6 49.0 26.9 Branta hylobadistes 1 4.9 10.8 52.0 30.1 Branta leucopsis 1 2.6 13.0 52.5 22.8 Branta ruficollis 3 2.6 9.3 37.6 26.9 Branta sandvicensis 3 3.0 10.9 57.9 26.4 Branta sp.* 2 5.4 13.7 87.6 24.0 Bucephala albeola 4 2.8 7.5 25.6 27.5 Bucephala clangula 4 2.5 10.7 39.5 24.2 Bucephala islandica 3 3.0 10.2 41.4 26.6 Cairina moschata 3 4.0 18.8 58.1 26.4 Cairina scutulata 4 5.8 14.6 56.0 25.3 Calonetta leucophrys 2 2.7 6.5 24.1 27.3 Cereopsis novaehollandiae 4 3.8 13.8 51.0 26.6 continued next page Species n nV foramen nII foramen Foramen magnum Palatine angle TABLE 2. (continued) (mm2) (mm2) (mm2) (°) Chenonetta jubata 3 1.6 8.2 30.1 26.5 Chloephaga hybrida 4 3.1 10.4 48.3 22.5 Chloephaga melanoptera 3 3.3 12.3 45.7 21.1 Chloephaga picta 3 2.7 12.7 46.8 19.2 Chloephaga poliocephala 3 2.3 13.0 40.4 15.8 Chloephaga rubidiceps 1 1.5 10.0 39.9 14.6 Clangula hyemalis 5 2.2 9.1 32.1 20.4 Coscoroba coscoroba 4 8.1 11.4 59.7 16.7 Cyanochen cyanopterus 4 3.0 12.5 48.3 19.4 Cygnus atratus 4 7.8 12.9 83.2 20.9 Cygnus buccinator 5 9.4 12.4 106.8 24.4 Cygnus columbianus 4 8.2 12.1 83.2 22.3 Cygnus cygnus 1 8.8 17.7 130.1 22.2 Cygnus melancoryphus 4 8.8 9.3 80.3 21.1 Cygnus olor 4 10.9 15.4 107.2 26.1 Dendrocygna arborea 4 5.4 11.3 42.6 23.6 Dendrocygna arcuata 4 4.7 7.3 35.2 19.8 Dendrocygna autumnalis 4 4.6 9.6 32.5 22.6 Dendrocygna bicolor 4 4.4 8.3 36.8 26.4 Dendrocygna eytoni 2 3.9 9.1 32.8 22.2 Dendrocygna guttata 4 5.5 9.0 29.8 25.9 Dendrocygna javanica 2 4.8 8.3 34.1 - Dendrocygna viduata 4 3.5 8.5 30.8 22.1 Heteronetta atricapilla 2 3.7 5.1 25.4 24.0 Histrionicus histrionicus 4 1.4 9.5 33.0 26.1 Hymenolaimus malacorhynchus 1 6.3 10.5 45.5 22.9 Lophodytes cucullatus 5 1.7 11.2 31.2 26.5 Lophonetta specularoides 4 5.5 7.8 39.1 24.5 Malacorhynchus membranaceus 1 5.9 5.2 27.4 20.4 Marmaronetta angustirostris 4 2.2 6.2 28.6 - Melanitta fusca 4 4.7 10.7 51.0 23.3 Melanitta nigra 4 3.1 9.5 40.8 17.3 Melanitta perspicillata 6 4.2 11.3 39.7 19.7 Merganetta armata 1 3.3 8.6 31.6 - Mergellus albellus 2 2.1 9.7 32.2 - Mergus merganser 5 1.5 14.2 43.2 24.1 Mergus octosetaceus 1 2.0 12.1 40.8 15.8 Mergus serrator 5 1.9 13.3 37.8 29.9 Neochen jubatus 4 2.5 12.8 42.7 21.6 Netta erythrophthalmica 4 2.4 9.6 41.6 31.4 continued next page Species n nV foramen nII foramen Foramen magnum Palatine angle TABLE 2. (continued) (mm2) (mm2) (mm2) (°) *undescribed species of Branta from the Hawaiian archipelago.

Netta peposaca 3 2.3	9.3	44.9	14.0
Netta rufina 4 3.5	10.5	38.5	13.3
Nettapus auritus 4 1.5	6.6	21.0	22.8
Nettapus coromandelianus 4 1.9	6.4	22.0	30.1
Nettapus pulchellus 1 1.7	5.7	20.3	23.7
Oxyura australis 1 7.0	5.8	35.1	24.6
Oxyura dominica 4 3.3	6.1	27.0	30.7
Oxyura jamaicensis 4 8.0	4.9	37.9	24.6
Oxyura maccoa 2 7.1	5.8	37.1	17.4
Oxyura vittata 2 6.5	4.1	38.8	24.1
Plectropterus gambensis 4 6.3	15.8	69.6	31.9
Polysticta stelleri 4 5.7	6.2	39.0	30.0
Ptaiochen pau 5 4.9	8.7	70.2	25.8
Pteronetta hartlaubi 2 3.2	14.1	41.7	37.5
Sarkidiornis melanotos 4 3.3	14.7	47.5	32.3
Somateria fischeri 3 4.9	10.0	48.6	24.1
Somateria mollissima 4 4.0	12.5	57.7	29.4
Somateria spectabilis 4 4.1	9.9	47.9	27.3
Stictonetta naevosa 4 6.0	7.2	34.6	26.5
Tachyeres brachypterus 3 7.3	13.2	70.1	25.7
Tachyeres leucocephalus 1 5.9	10.2	70.4	26.0
Tachyeres patachonicus 2 7.8	10.9	54.5	22.6
Tachyeres pteneres 3 7.6	16.2	76.5	20.5
Tadorna cana 4 3.7	11.1	40.1	16.9
Tadorna ferruginea 4 4.0	9.9	39.2	20.8
Tadorna radjah 4 5.6	10.5	32.8	24.9
Tadorna tadorna 4 4.3	8.9	36.5	25.9
Tadorna tadornoides 2 4.3	10.6	46.4	26.3
Tadorna variegata 3 4.3	8.6	47.8	20.6
Thalassornis leuconotus 2 6.4	7.6	48.6	20.7
Thambetochen chauliodous 1 6.8 Talpanas lippa 1 15.4	10.7 2.3	79.4 35.0	31.5 42.3

TABLE 3. Samples sizes (n), body masses and mean measurements of 81 species that were used to estimate the body mass of Talpanas lippa . Data for Talpanas lippa are shown in bold.

Species	n	Body mass (g)	Tibiotarsal circumference (mm)	Tarsal length (mm)	Acetabular area (mm2)	Tarsal circumference(mm)
Aix galericulata	2	499.6	17.0	38.3	13.2	11.4
Amazonetta brasiliensis	2	595.0	14.8	35.9	15.0	10.5

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