Comparative Skull Anatomy
African Lion and Saltwater Crocodile
Dentition
Teeth Shape
Crocodiles have pointed, conical shaped teeth and they vary from blunt and dull to sharp and needle-like.
Crocodiles are often mistaken for alligators and an easy way to distinguish between them is by looking at their jaw line. Both the upper and lower teeth of a crocodile are visible when the mouth is shut.
Adult crocodiles can have up to 80 teeth.
Teeth Replacement
Teeth are replaced constantly over their lifetime. In juveniles the teeth can be replaced in as little as 3-4 months.
This process gets slower with age and as an adult the replacemnt process can be as slow as 20 months.
There is possibly a limit on how many times dentition can be replaced and there have been reports of old toothless crocodiles.
Due to this replacement of teeth crocodiles are referrred to as polyphyodonts.This replacement of Crocodiles teeth is a process starting from the back of the oral cavity towards the front.
Next to each full grown tooth, there is a small replacement tooth and a stem cell in the dental lamina. These structures within the skull are on standby and can be activated if and when new teeth are required.
Hunting for Prey
Crocodiles feed by grabbing and holding onto their prey. Having evolved sharp teeth, it allows them to pierce the flesh of their prey and hold on. When the crocodiles roll their prey while underwater this tears meat off the prey.
Powerful muscles close the jaws and hold them shut, ensuring the the prey is held tightly. Crocodiles can exert 1000lbs of pressure and their jaw strength is thought to have rivaled the Tyrannosaurus Rex.
Crocodile teeth are not designed for chewing, as their jaw is unable to move from side to side.
However the teeth are not well-suited to tearing flesh off of large prey items, compared to those many mammalian carnivores. Although this also works to the crocodiles advantage rather than a disadvantage, since the properties of the teeth allow prey to be held with the least possibility of the prey animal escaping. As such if the flesh was cut through completely, it would give the prey an opportunity to escape.
Sweat Glands
Crocodiles do not have sweat glands and release heat through their mouths.
Lion
Teeth Shape
Lions have long pointed teeth to grip their prey and sharp teeth for cutting up meat. Lions do not have flat teeth, which other animals use for chewing, as they swallow their food in chunks.
Lions have 30 adult teeth that are composed of 12 incisors, four canines, 10 premolars and four molars.
Teeth Replacement
The permanent teeth of a lion begin to break through the gums at 3 months of age and continue to develop until age 13 to 15 months.
Lions have deciduous dentition, in which the baby teeth are replaced like adult teeth
Hunting for Prey
Lions most frequently use suffocation to catch their prey, using it's bite to crush the prey's windpipe. Lions can exert 690lbs of pressure.
As soon as the prey is dead, a single lion will often drag it's catch to a less open spot and the meal proceeds. The killing and tearing of flesh is the reason lions have mostly pointy teeth.
Lions may consume up to 30kg of meat during a single feed.
Sweat Glands
Lions have very few sweat glands, despite the searing African heat. As an alternative to the lack of sweat glands they can pant up to 200 times a minute to cool themselves down.
Drawing showing the lateral view of the African Lion skull with the teeth colour coded as follows:
Red teeth= Incisors
Green teeth= Canines
Blue teeth= Pre-molars (2,3&4)/Carnissals
Lateral (side on) view of a saltwater crocodile skull drawing with the canines shown in green.
Crocodile
Drawing showing the position of the canines (teeth) of the saltwater crocodile when the mouth is closed.
Photograph showing the teeth of the African Lion.
Photograph showing a lateral view of a saltwater crocodile skull.