Like tamarins, marmosets are among the smallest primates, with average head and body lengths between 7 and 7 ½ inches. They weigh between 8 and 9 ½ ounces with the males being slightly larger than the females. The coat, or pelage, of the marmoset is a blotchy brown, grey, and yellow. They also have white ear tufts and long banded tails. Unlike many other New World primates, marmosets do not have a prehensile tail. Their faces have pale skin with a white blaze on the forehead. At birth, infants have brown and yellow coats and develop the ear tufts as they age. In form, members of the callitrichid family, marmosets resemble other primates that cling vertically to trees. The forelimbs are shorter than the hind limbs, but most locomotion is quadrupedal, meaning all four limbs are specialized for walking and climbing. The hands and feet resemble those of squirrels. The thumb and big toe are not opposable. The surfaces of the hands and feet are long relative to the digits. Additionally, all of the digits except the big toe, called a hallux, have sharp claws, not the flattened nails found in many other primates. Callitrichids use these claws to dig into the bark of trees. Callitrichines also are unique in having enlarged, chisel-shaped incisors and specialized digestive systems for their diet.