. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 174 ANNALS OF THE SOUTH AFRICAN MUSEUM. Fig, 11. H. tucki. A. Right humerus, dorsal view. B, Right manus, medial view. Scales: A = 5 cm: B = 2,5 cm. twisted about its long axis, so the transverse axis of the proximal and of the distal articular surfaces are virtually parallel. The proximal part of the shaft with the deltopectoral crest is retroflexed relative to the distal part; the angle formed is about 30°. Proximally, the humerus has a moderately well-developed articular head, bounded laterally by
. Annals of the South African Museum = Annale van die Suid-Afrikaanse Museum. Natural history. 174 ANNALS OF THE SOUTH AFRICAN MUSEUM. Fig, 11. H. tucki. A. Right humerus, dorsal view. B, Right manus, medial view. Scales: A = 5 cm: B = 2,5 cm. twisted about its long axis, so the transverse axis of the proximal and of the distal articular surfaces are virtually parallel. The proximal part of the shaft with the deltopectoral crest is retroflexed relative to the distal part; the angle formed is about 30°. Proximally, the humerus has a moderately well-developed articular head, bounded laterally by the superior margin of the deltopectoral crest and medially by a tuberosity lying just below the articular eminence. The head lies in the middle of the superior surface; its diameter is greater than the thickness of the proximal end of the shaft and a small fossa occurs just below the head anteriorly while a buttress of bone lies below the head posteriorly. The deltopectoral crest occupies about 40 per cent of the lateral margin of the humerus; it ends abruptly and joins the shaft at nearly a right angle. The crest is directed anteriorly as well as laterally, so the anterior surface of the crest and shaft is concave, the posterior surface convex. The edge of the crest is thin except superiorly where it forms part of the tuberosity (for the insertion of the deltoid) and inferiorly where it is rugose and thickened for the attachment of the pectoralis muscle. Below the deltopectoral crest the shaft is subcircular in cross-section; it becomes more rectangular distally as the supracondylar area is approached. The medial, ulnar condyle is gently rounded both transversely and antero- posteriorly; it extends somewhat lower than the radial condyle. The radial condyle is ridge-like transversely, not rounded; a transverse section through the condyles would thus show a U-shaped ulnar condyle meeting a V-shaped radial condyle. While the anteroposterior axis of the ulnar condyle is parasag
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectnaturalhistory, booky
