Comparative Skull Anatomy
African Lion and Saltwater Crocodile
The main and only muscle that opens a lion’s jaw is the Digastricus muscle. Its origin is the occipital bone at the base of the skull and attaches to the mandible (jaw) bone.
There are 4 muscles associated with closing a lion’s jaw:
The masster
Lateral pterygoid
Medial pterygoid
Temporal muscle
Crocodile
The crocodile’s jaw is arranged for clamping down, especially to produce a ‘snap shut’ motion. Interestingly, even though crocodile’s have strong muscles for closing the jaw, they have incredibly weak muscles that control opening the jaw. They can be held shut with as little as a rubber band!
Crocodile’s can achieve a wide gape because of their medial and lateral pterygoid muscles.
The temporalis muscle inserts at holes at the superior of the skull, called supratemporal fenestrae, and go straight down to attach to the anterior of the jaw joint. This muscle allows the crocodile to produce a small gape.
Lion
Photograph showing the jaws and teeth of a saltwater crocodile skull.