A preorbital vacuity of such dimensions as to exclude the lachrymal bone from articulation with the nasal.
The astragalus has a pulley-like surface above for articulation into the tibia, but its lower surface is flattened and unites to a much greater extent with the navicular than with the cuboid, which bone is of comparatively less importance than in the Artiodactyles.
The articulation between the tibia and astragalus is more complex than in other mammals, the end of the malleolus entering into it.
When this attachment takes place by an articulation, the petals fall off either immediately after expansion (caducous) or after fertilization (deciduous).
Its proximal end forms a shallow cup for articulation with the outer condyle of the humerus; the distal end bears a knob which fits into the radial carpal.