The fourth erupts and begins to function during the animal's fourth or fifth year. It moves forward gradually in the jaw, and is replaced after eight years by the fifth tooth. The sixth and last molar erupts when the elephant is about 25 years old. Only one molar is fully functional at a time. Each successive tooth is larger and more complex.
Elephants chew with a fore and aft motion of the jaw, grinding the food across the lophs.
The skull of modern elephants is short and high. The bone over the top of the head contains numerous air cells. The skeleton of elephants is adapted to bear massive weight, and as well, to provide attachments for the muscles required by an animal that may feed by pushing over and uprooting entire trees. The orientation of the pelvis is also modified. Elephants require huge amounts of food, over 400 kg per individual per day.