the arch running under the orbit and temporal fenestra in synapsids. Same as subtemporal arch, and roughly equivalent to the jugal arch in diapsids. Normally formed from jugal and squamosal (maxilla & squamosal in multituberculates). The presence of a zygomatic arch, at least when bowed outward, implies the presence of the masseter muscle which permits chewing of food.
The zygomatic arch, or cheekbone area, is formed by the zygomatic process of temporal bone (a bone extending forward from the side of the skull, over the opening of the ear) and the temporal process of the zygomatic (the side of the cheekbone), the two being united by an oblique suture; the tendon of the Temporalis passes medial to the arch to gain insertion into the coronoid process of the mandible.