Some Morphological Studies on the Jaw Joint of the Australian Saltwater Crocodile (Croco- dylus porosus)

The saltwater crocodile is the largest of all living reptiles. It is also known and proved that it has the largest biting forces. The magnitude of the biting force exerted by the jaw leads to thoughts about the anatomical structure and construction of the jaw joint in this reptile. Thirteen skulls of the saltwater crocodile (C. porosus) were used for this study. Some skulls were used for X-raying and morphology, and the others for histological slides which were prepared from the articular cartilages, capsule and collateral ligaments. The quadrate/articular joint (jaw joint) was diarthroidal, formed by two articular surfaces, which were fibrocartilage in nature at the periphery of the articular surface, hyaline in the rest of the articular surface, and ossifies on reaching the underlying bone. The thick lateral and thin medial collateral ligaments were formed of collagenous fibers. An articular disc was missing in the crocodile quadrate/articular joint. The joint was surrounded by a complex massive group of muscles responsible for the firm closure and opening of the mouth. The results were supported by 10 images and 4 tables, and were discussed with other amphibians, domestic animals and man when needed.