An assessment of joint excursions and fin postures and functions in
Tiktaalik is made possible by the preservation, in multiple specimens,
of complete bony articular surfaces of all the major joints of the
shoulder and fin (Fig. 6). The excursions possible at each joint may be
inferred from the articular geometry, in particular the curvatures of
apposing cartilage-covered surfaces. Although this soft tissue is not
preserved, the curvature is unlikely to have been less than that
preserved as the bony supporting surface of the joint, and could
possibly have been greater.