surangular bone

The surangular is a dermal bone of the lower jaw. It typically covers much of the dorsal and lateral surface of the posterior jaw and variably extends onto the medial (inside) surface. The surangular articulates with and supports the articular, which forms the jaw joint with the quadrate in most vertebrates, and is in turn supported by the angular. More distally, the surangular bridges the mandibular fenestra, if one is present. It may also bear a raised dorsal coronoid process, an important attachment site for the mandibular adductors. At its distal (or rostral) end, the surangular meets the dentary, the main tooth-bearing bone of the lower jaw in most vertebrates.