The surangular is a long, flat element of the mandible. It forms the lateral portion of the articular fossa of the jaw joint. The lateral edge of the articular fossa bears a pronounced scar for the lateral collateral ligament of the jaw joint. The surangular has a broad flat shelf on its dorsal surface for the attachment of the adductor mandibulae externus sperficialis muscle. Ventrally, it forms the rim of the external mandibular fenestra.