Size
Lemurs are the smallest primates. The mouse lemur is so small it can fit in the palm of a human hand. The largest lemur, the ring-tailed lemur, weighs approximately 15 lbs. when full-grown. The size of the lemur in comparison to other primates is an adaptation to the limited space on the island where it evolved. In proportion to its small size, the lemur also has a very small brain.
Movement
Because lemurs spend most of their lives in trees, the animal has strong hands and feet for climbing. Their hind limbs are muscular to aid jumping from branch to branch. They can twist their bodies in midair to grab branches at different angles. Since lemurs are adapted to climbing and jumping, many lemurs cannot walk up right. The sifaka lemur hops sideways on its back legs to overcome its inability to walk bipedally.
Scent Glands
Unlike most primates, lemurs have scent glands on their wrists, chest and below their tail. They communicate with each other through the use of these scent glands, which includes rubbing their scent glands on trees and bushes to mark territory. The lemur's nose is long, hairless and wet to facilitate communication through scent.
Grooming
Like most primates, lemurs groom each other as a social bonding activity. However, lemurs do not have the manual dexterity of monkeys and humans with their four fingers and opposable thumb. As such, the lemur has a long claw on its second finger for grooming called the "toilet claw." In addition, the lemur's front teeth are long and narrow and jut forward to enable combing through their fellow lemurs' hair.