Reconstruction of the pectoral girdle of Diplodocus.
Abstract : The orientation of the scapulocoracoid in sauropod dinosaurs is reconstructed based on comparative anatomical investigations of pectoral girdles of extant amniotes. In the reconstruction proposed here, the scapula of sauropods stands at an angle of at least 55° to the horizontal plane in mechanical coherence with the sternal apparatus including the coracoids. The coracoids are oriented cranioventrally to the rib cage and the glenoid is directed mediolaterally, which allows the humerus to swing in a sagittal plane.
Reconstruction of the pectoral girdle of Camarasaurus.
The inclination of the scapula to the horizontal plane is reconstructed for Diplodocus (60-65°), Camarasaurus (60-65°), and Opisthocoelicaudia (55-65°). The inclination of the scapulocoracoid has consequences for the overall body posture in Camarasaurus and Opisthocoelicaudia, where the dorsal contour would have ventrally declined toward the sacrum.