FIGURE A1. NMNZ S.47302, 1, the extent of the specimen that has been physically prepared, 2, the three-dimensionally rendered elements within the block. Fossils numbered in 2 are as follows: 1, coracoid; 2, unidentified, possibly a radiale; 3, sternum; 4, furcula; 5, mandible; 6, cervical vertebra; 7, unidentified; 8, unidentified; 9, cervical vertebra IV; 10, unidentified. Scale bar is equal to 50 mm.
FIGURE A2. NMNZ S.47303, 1, the extent of the specimen that has been physically prepared, 2, the three-dimensionally rendered elements within the block. Fossils numbered in 2 are as follows: 1, ischium; 2, manus phalanx III-1; 3, radius; 4, radius; 5, cervical vertebra, Table 1 cervical (iv), Figure 2.25-30; 6, cervical vertebra, Table 1 cervical (iii), Figure 2.19-24; 7, carpometacarpus; 8, cervical vertebra, Table 1 cervical (ii), Figure 2.13-18; 9, possibly cervical vertebra III, Table 1 cervical (i), Figure 2.7-12; 10, manus phalanx II-1; 11, rib; 12, caudal vertebra; 13, axis. Scale bar is equal to 50 mm.
FIGURE A3. NMNZ S.47303 in Materialise Mimics, cross-sectional view of right radius (Figure 5.7, 5.9-10) in top two images, 1, and left radius (Figure 5.6-11) in two lower images, 2. Cross-sectional perspective reveals a reduced marrow-cavity compared to modern aerially flighted birds, but not as dense as extant penguins.
FIGURE A4. How specimens associated with Kupoupou stilwelli n. gen. et sp. are linked together through overlapping elements.
FIGURE A5. Undescribed vertebrae and ribs referred to Kupoupou stilwelli n. gen. et sp. 1-7, vertebrae, NMNZ S.47339; and 9 and 10, ribs, NMNZ S.47339. 8, an incomplete vertebra, is part of NMNZ S.47302, associated with the larger Chatham Island form. Scale bar is equal to 10 mm.
FIGURE A6. Majority-rule consensus (50%) tree treating NMNZ S.47302 and S.47304 as separate taxa (13,600 MPTs, L = 5,233 steps, CI = 0.5251, RI = 0.7020). Percentage of MPTs recovering each node is indicated at each internode in the consensus tree, and bootstrap support values (over 40% only) are numbered below them italicised in red.
FIGURE A7. Majorite-rule consensus (50%) tree excluding character scores relating to referred material of Eocene Seymour Island taxa (400 MPTs, L = 5,212, RI = 0.7014, CI = 0.5272). Percentage of MPTs recovering each node is indicated at each internode in the consensus tree, and bootstrap support values (over 40% only) are numbered below them italicised in red.
FIGURE A8. Strict consensus tree of 16,300 MPTs (length = 5,234). Bootstrap support values (over 40% only) are numbered below each node italicised in red.
FIGURE A9. A sample of the variety of equally parsimonious phylogenetic relationships recovered between Paleocene taxa (length = 5,234).
FIGURE A10. Specifics of referred hypotarsal morphology. 1, Diomedea antipodensis left (mirrored, adapted from Mayr, 2016); 2, Aphrodroma brevirostris, left (mirrored, adapted from Mayr, 2016); 3, Hydrobates castro, left (mirrored, adapted from Mayr, 2016); 4, Waimanu manneringi, right, CM zfa35; 5, Muriwaimanu tuatahi, right, 2009.99.1 (.STL file, tomographic rendering); 6, Marambiornis exilis, right, IB/P/B-0490 (modified from Jadwiszczak, 2015); 7, Delphinornis gracilis, right, IB/P/B-0279a; 8, Anthropornis nordenskjoeldi, MLP 95-I-10-142 (mirrored, modified from Jadwiszczak, 2015); 9, Palaeeudyptes klekowskii, IB/P/B-0485 (mirrored, modified from Jadwiszczak, 2015); 10, Palaeeudyptes antarcticus, right, BM A.1048; 11, Palaeospheniscus bergi, NHMUK A694 (mirrored, modified from Jadwiszczak, 2015); 12, Spheniscus magellanicus, NHMUK 2001.45.1 (mirrored, modified from Jadwiszczak, 2015); 13, Eudyptes chrysocome, NHMUK 1898.7.1.15 (mirrored, modified from Jadwiszczak, 2015); 14, Aptenodytes forsteri, NHMUK 1905.12.30.419 (mirrored, modified from Jadwiszczak, 2015); 15, Pygoscelis adeliae, unassigned from IB/P/B (mirrored, modified from Jadwiszczak, 2015); abbreviations: cl(fdl), crista lateralis flexoris digitorum longus; cl(fhl), crista lateralis flexoris hallucis longus; cm(fdl), crista medialis flexoris digitorum longus; fbl, sulcus for musculus fibularis longus; fdl, sulcus/canal for tendon of musculus flexor digitorum longus; fhl, sulcus/canal for tendon of musculus flexor hallucis longus; tfb, tuberculum musculus fibularis brevis. Dotted line represents estimated extent of bone. Not to scale.
