The temporal ligaments and their bearing on cranial kinesis in lizards



In the lateral temporal opening of the lacertilian skull there are three main types of ligaments: quadratojugal, jugomandibular, and quadratopostfrontal. The quadratojugal and ventral jugomandibular ligaments transmit the retraction force from the lower jaw to the rhinal unit of the maxillary segment. The dorsal jugomandibular ligament causes the coupled kinesis, that results in the protraction of the whole maxillary segment (in the amphikinetic skull with simple streptostyly) or in the protraction of the quadrate-mandibular complex (in the hyperstreptostylic skull), when opening the mouth.