FIGURE 6 in A new fossil subspecies of booby (Aves, Sulidae: Papasula) from Mauritius and Rodrigues, Mascarene Islands, with notes on P. abbotti from Assumption Island

FIGURE 6. Comparison of ulnae of Papasula a. nelsoni ssp. nov. with Papasula a. abbotti, left side, A, B, C, ventral aspect, D, E, F, dorsal aspect. A & D. USNM 560862 P. a. abbotti immature u/s (Christmas Island); B & E. USNM 560863 P. a. abbotti u/s (Christmas Island); C & F UMZC 262.AA paratype P. a. nelsoni (Mare aux Songes, Mauritius). Abbreviations: ib, impressio brachialis; prv, papillae remigales ventralis; si, sulcus intercondylaris; dr, depressio radialis; cv, cotyla ventralis; tc, tuberculum carpale; cvu, condylus ventralis ulnaris. Scale bar = 20 mm.