Figure 1. Selected skeletal elements of Rupelornis definitus in comparison to extant Procellariiformes. A, B, R. definitus, proximal end of right mandible (IRSNB Av 109a) in dorsal (A) and mediodorsal (B) view. C, proximal mandible of Puffinus huttoni (Procellariidae). D, right quadrate of P. huttoni. E, R. definitus, thoracic vertebra (IRSNB Av 109b). F, thoracic vertebra of P. huttoni. G-I, R. definitus, sternum (IRSNB Av 104a) in ventral (G), dorsal (H), and craniodorsal (I) views. J, R. definitus, left coracoid (IRSNB Av 107b) in dorsal view. K–M, R. definitus, left coracoid (IRSNB Av 112a) in dorsal (K), medial (L), and ventral (M) views. N, R. definitus, left scapula (IRSNB Av 102f) in lateral view. Abbreviations: amq, attachment area of musculus adductor mandibulae ossis quadrati; cas, rostrally projecting, concave articular surface of condylus medialis; cic, crista intercotylaris; cmd, cotyla medialis; csc, cotyla scapularis; ctl, cotyla lateralis; cvx, convex dorsal surface of extremitas omalis, between cotyla scapularis and tip of the processus acrocoracoideus; fns, foramen nervi supracoracoidei; for, large foramen in cranial portion of ventral surface of corpus sterni; fos, fossa on corpus of thoracic vertebra; lbi, labrum internum; rdg, ridge between the proximal end of cotyla medialis and tuberculum pseudotemporale; spe, spina externa; tpt, tuberculum pseudotemporale. Fossil bones are coated with ammonium chloride. Scale bars = 10 mm.