The arch formed by the malar bone and the zygomatic process of the temporal bone.
"A Practical Physiology" by Albert F. Blaisdell
The coronoid process is displaced below and behind the zygomatic (malar) bone, and may be felt through the mouth.
"Manual of Surgery Volume Second: Extremities--Head--Neck. Sixth Edition." by Alexander Miles
Zygomatic processes of jugal bones thick and massive.
"Encyclopaedia Britannica, 11th Edition, Volume 5, Slice 7" by Various
In the horse, it articulates with the zygomatic process of the temporal bone.
"Artistic Anatomy of Animals" by Édouard Cuyer