Figure 5. Changes humerus shape in saurischian dinosaurs and alligators.

Maximum humerus shape change in the sample is shown on the Y-axis (PRIN 1), whereas humerus shape changes associated with size are shown on the X-axis. Changes in humerus shape along the PRIN 1 axis and X-axis are similar in that larger taxa have more proximally and distally expanded ends. In particular, the sub-articular region expands tremendously whereas its overall shape remains gently convex. Note also that the deltopectoral crest (landmarks 2–4) remains or becomes more medially-deflected as size increases.