They have webbed feet which, though not used to propel the animal through the water, allow them to make fast turns and sudden moves in the water or initiate swimming.
Webbed feet are an advantage in shallower water, where the animal sometimes moves around by walking. Crocodiles have a palatal flap, a rigid tissue at the back of the mouth that blocks the entry of water.
The palate has a special path from the nostril to the glottis that bypasses the mouth. The nostrils are closed during submergence.
Like other archosaurs, crocodilians are diapsid, although their post-temporal fenestrae are reduced. The walls of the braincase are bony, but lack supratemporal and postfrontal bones.
Their tongues are not free, but held in place by a membrane that limits movement; as a result, crocodiles are unable to stick out their tongues.
Crocodiles have smooth skin on their bellies and sides, while their dorsal surfaces are armoured with large osteoderms. The armoured skin has scales and is thick and rugged, providing some protection. They are still able to absorb heat through this armour, as a network of small capillaries allows blood through the scales to absorb heat.
Crocodilian scales have pores believed to be sensory in function, analogous to the lateral line in fishes. They are particularly seen on their upper and lower jaws. Another possibility is that they are secretory, as they produce an oily substance which appears to flush mud off
