All articulated hadrosaurian skeletons expose a comparatively abrupt ventral flexure of anterior thoracal portion of the vertebral column. This resulted in effective shortening of the body anterior to the acetabulum and in shifting backward the gravity center of the heavy thoracal part, in deepening of pleural cavity as well as in lowering the suspension point of the fore limb at the glenoid, making easier access of the fore limb to the ground. In some hadrosaurs at least, sacropelvic contact was strengthened by a forward extension of the acetabular bar, so that pubis also was keyed to sacrum by a sacral rib, and the puboiliac contact was re inforced. This enabled these hadrosaurs to assume and sustain a stance with the vertebral column inclined upwards.

Key words: dinosaurs, Hadrosauridae, Upper Cretaceous, anatomy.