The |parietal bones| are two of the flat cranial bones that form the roof and upper sides of the skullcap (calvarium). The |parietal bones| are attached to each other by the |sagittal suture| which runs longitudinally along the roof of the |skull|, and both of the |parietal bones| are attached to the |frontal bone| by the |coronal suture| and to the |occipital bone| in back by the |lambdoid suture|. The sphenoid and |temporal bones| on each side of the |skull| are attached to the lower edge of the |parietal bone| by the |squamous suture|. Two ridges traverse the side of the |parietal bone|, extending to the |frontal bone| and forming a depression with the temporal |fossa|. These two ridges are called the superior (top) and inferior (bottom) |temporal lines|.