Caudalmost thoracic vertebrae of procellariiform (A‒E) and charadriiform (F‒M) birds in right lateral view. A, Diomedea melanophris (Diomedeidae; SMF 7570). B, Macronectes halli (Procellariidae; SMF 8949). C, Daption capense (Procellariidae; SMF 3728). D, juvenile Calonectris diomedea edwardsii (Procellariidae; SMF 932). E, Calonectris diomedea borealis (Procellariidae; SMF 8486). F, Rynchops niger (SMF 4756). G, Larus audouinii (Laridae; SMF 2444). H, Larus fuscus (Laridae; SMF 2390). I, Anous stolidus (Lari; SMF 10146). J, Himantopus himantopus (Recurvirostridae; SMF 1705). K, juvenile Numenius arquata (Scolopacidae; SMF 9901). L, Numenius arquata (Scolopacidae; SMF 20378). M, Catharacta antarctica (Stercorariidae; SMF 19187). Abbreviations: lop, lateral openings; plc, pleurocoel. The scale bars equal 10 mm.