Axial skeleton anatomy. The adult axial skeleton consists of 80 bones. It’s made up of the bones that form the vertical axis of the body, such as the bones of the head, neck, chest, and spine.

Figure 4: MGUH VP 6139, skull, shoulder girdle, thoracic and presacral region of Ichthyostega. If we are correct and the axial morphology did not permit lateral trunk flexion in Ichthyostega, two ...