Posterior view of the temporal fossa and pterion. At the anterior edge of the squamosal suture, the articulation between the squamous temporal bone and the parietal bone, is the pterion. The pterion is the H-shaped region where four cranial bones meet: the squamosal portion of the temporal bone, the greater wing of the sphenoid bone, and the frontal and parietal bones. The coronal suture runs superiorly at the junction of the frontal and parietal bones. The zygomatic arch is formed by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone. (Image courtesy of AL Rhoton, Jr.)