A marmoset is a member of the family of primates and are known to be one of the smallest monkey. They are measured to have a body length of 12 - 15 inches and has a mass of approximately 100 - 125 g. Comparing to monkeys, marmosets have distinct characteristics. Instead of having nails, they have claws, they tactile hair or a sensitive hair found on their wrists. They do not have wisdom teeth and the layout of their brain is primitive.