Elephants: Proboscidea

Elephants weigh 200 to 265 pounds (90 to 120 kilograms) when they are born. Even after they reach adulthood, elephants continue to grow. Females stop growing between twenty-five and thirty years and males between thirty-five and forty-five years. Adult females weigh anywhere from 3.3 to 7.7 tons (3 to 7 metric tons), depending on the species of elephant.

When compared to the size of its body, an elephant's head is large. It weighs up to half a ton (half a metric ton) and is supported by a short neck. Elephants have four, very strong legs with feet containing five splayed, spread out, toes. The toes are buried inside the flesh of the foot so that they are invisible to the naked eye. When elephants stand, they are actually on their tip-toes, and though the first visible joint looks like a knee, it is more like a wrist or ankle. Elephant feet also have pads of tissue to help support their massive weight. The long tail ends in a cluster of coarse, rough, hair.

Elephants have no sweat glands, but their large ears contain a great number of blood vessels to assist with heat loss to help keep them cool. Their gray hide is sparingly covered with tiny, short hairs.

The tusks of an elephant are actually teeth and are covered in dentin, a material that is harder than bone. A third of each tusk is hidden inside the skull, and additional dentin forms there, pushing each tusk out at a rate of up to 6 inches (15 centimeters) yearly. The tusks of a male elephant can weight 110 pounds (50 kilograms) each and measure 79 inches (200 centimeters). If an elephant were human, its trunk would be comparable to the nose and upper lip. The trunk is extremely sensitive and flexible and contains no bone or cartilage. Instead, it is made up of about 150,000 moveable muscles, which makes it incredibly powerful. An elephant's nostrils run the whole length of the trunk.