Fig. 1

Wing and pectoral girdle bones of the new giant penguin. a K. biceae n. gen. et sp. (holotype, NMNZ S.45877) from the Paleocene of New Zealand, partially prepared concretion with all bones in situ. b K. biceae (holotype), right coracoid in dorsal view (dotted lines indicate reconstructed outline of bone). c Left coracoid of Waimanu tuatahi from the late Paleocene of New Zealand (CM zfa 34; specimen mirrored to ease comparisons). d–f Fragmentary proximal end of the left ulna of K. biceae in (d) dorsal, (e) ventral, and (f) proximal view. g, h Left ulna of an undescribed new sphenisciform from the Waipara Greensand (CM 2016.6.1) in (g) ventral and (h) proximal view; the dashed line in g indicates the portion of the bone preserved in the K. biceae holotype. i CT image of cranial surface of partial left humerus. j Exposed caudal surface of the bone, surrounding bones and matrix were digitally brightened. k, l CT images of caudal humerus surface with (k) minimum and (l) maximum length estimates based on the reconstructed outline of the bone (dotted lines). m Left humerus of Crossvallia unienwillia from the late Paleocene of Antarctica (holotype, MLP 00-I-10-1), which is one of the largest previously known Paleocene penguin species. n Left humerus of Pachydyptes ponderous from the late Eocene of New Zealand (holotype, NMNZ OR.1450), which was previously considered one of the largest fossil penguins. Abbreviations: cor, coracoid; dcp, dorsal cotylar process; fem, femur; fpt, fossa pneumotricipitalis; hum, humerus; olc, olecranon; ppc, procoracoid process; scc, scapular cotyla; sup, attachment scar for supracoracoideus muscle; tbt, tibiotarsus; vct, ventral cotyla. Scale bars equal 50 mm; same scale for b and c, f and h, and i-l, respectively