The bones of the skull, exploded and mounted.
Though we often think of the cranium as a single hollow bone, this is not in fact the case. Indeed, at one point in your life, these bones existed as entirely separate, independent structures.
Through your early years, these unconnected bones joined together in your head to form that single, rigid cage.
The work of Ryan Matthew Cohn, pictured, shows the effect when the connecting sutures are unstitched and the parts brought apart once more. The serrated edges of some bones, visible particularly in the second image, are the faults along which these almost completely inflexible joints once existed.