Animals With Flexible Thumbs
Humans Humans not only have opposable thumbs, but we can use our thumbs and hands in ways that animals cannot. Bring your thumb across your palm to touch the base of your ring finger and pinky finger.
Apes The great apes, including the gorilla, chimpanzee, bonobo, orangutan, and lesser apes called gibbons, all have opposable thumbs. In fact, they take opposable digits a step further – the big toe of the foot is opposable as well!
Old World Monkeys Old World monkeys are those species native to Asia and Africa, as opposed to the New World monkeys of the Americas. There are twenty-three Old World monkey species, and most, including grivets, baboons, and macaques, use their opposable thumbs for grasping tree branches and other objects.
Lemurs Lemurs are primates found only on the island of Madagascar and a few other islands off the coast of Africa. The smallest of the 100 or so lemur species is only 3 inches in length, while others are several feet tall. Some researchers refer to the lemurs’ thumbs as “pseudo-opposable thumbs,” meaning that they are almost opposable but not quite.
Chameleons Chameleons use the special thumblike arrangement of the toes on their feet to grasp twigs and branches as they climb. Three toes make up the “medial bundle,” extending from the middle section of the foot. Two toes make up the “lateral bundle,” extending to the side.
Koalas The koala, the famed marsupial of Australia, is unlike any other animal in that it actually has two opposable thumbs. These thumbs are set at an angle to the three fingers. The koala uses these two sections of its hand – the thumbs and fingers – to securely grasp and climb tree branches.
Giant Pandas Giant pandas (Ailuropoda melanoleuca) have an opposable thumb that has been called a false thumb. Rather than consisting of the distal and proximal phalange bones, the panda’s false thumb is an enlarged carpal bone – one of the many bones that together form the wrist.
Possums and Opossums Virginia opossums have a number of unique features. They are the only marsupial in North America, carrying young in a pouch like a kangaroo. They have grasping prehensile tails and opposable thumbs (actually, it is the fifth toe) on their hind feet. Together, the tails and thumbs aid them in climbing trees to hunt or escape danger. Interestingly, the opossum’s opposable thumb lacks a nail or claw.
Waxy Monkey Leaf Frogs Arboreal or tree-dwelling frogs of the family Phyllomedusa are one of only two non-mammals to make our list. These arboreal amphibians, which have a penchant for laying their eggs in a leafy parcel, can be found in Argentina and Panama.
New World Monkeys A few New World monkeys – those living in the Americas – have opposable thumbs. These include the saki, ukari, tamarin, woolly monkey, night monkey, owl monkey, capuchin, and squirrel monkeys. Like lemurs and lorises, some of these monkeys are classified as having pseudo-opposable thumbs.