Fig. 8. Comparison of loading regimes on bones and ligaments of the equid carpus and tyrannosaurid arctometatarsus. Tyrannosaurid intermetatarsal ligaments are analogous in position and function with the interosseous ligaments of the horse carpus. a: Anterior view of left horse carpus, showing wedge-like articulations between carpals and dorsal ligaments (dl) connecting them. Modified from Sisson and Grossman (1953). b: Diagrammatic midfrontal section through horse carpus shows stretching (white arrow) of deep interosseous ligaments upon compressive loadings (black arrows) of the wrist. Inset shows how compression on the radius (R) and third carpal (C3) causes the wedge-like dorsal surface of C3 to laterally displace the radial and intermediate carpals (Cr and Ci). A portion of the compressive force is translated into tensile loading (white arrows) on the interosseous ligament between Cr and Ci. Modified from Sisson and Grossman (1953). c: A plurality of ground-reaction loadings (black arrows) is imposed on the tyrannosaurid MT III, the central element in this diagram. Loading differentials between MT III and MT II and MT IV, respectively, cause tensile stresses on intermetatarsal ligaments (white arrows).