in lateral side of zygomatic arch https://upload.wikimedia.org/wikipedia/commons/f/f4/Gray188-Sphenozygomatic_suture.png The zygomatic arch is significant in evolutionary biology, as it is part of the structures derived from the ancestral single temporal fenestra of the synapsid ancestor of mammals. FMA:53120 arcus zygomaticus MA:0002810 UBERON:0002500 EMAPA:36570 zygoma MESH:D015050 SCTID:272682006 MFMO:0000108 The bony arch in vertebrates that extends along the side or front of the skull beneath the eye socket and is formed by the temporal process of the zygomatic bone and the zygomatic process of the temporal bone. NCIT:C33897 Wikipedia:Zygomatic_arch The zygomatic arch is occasionally referred to as the zygoma, but this term usually refers to the zygomatic bone or occasionally the zygomatic process. The zygomatic process of the temporal arises by two roots: an anterior, directed inward in front of the mandibular fossa, where it expands to form the articular tubercle. a posterior, which runs backward above the external acoustic meatus and is continuous with the supramastoid crest. The upper border of the arch gives attachment to the temporal fascia; the lower border and medial surface give origin to the Masseter UMLS:C0162485 galen:Zygoma facial bone facial skeleton neurocranium bone lateral structure