There are a few characteristics that animals develop that give them a true advantage in their world. The Giraffe for example, has it’s incredible neck which gives it a massive advantage for eating from high up, uncontested branches. Some octopus, fish and lizards have the ability to change the color of their skin to camouflage into the background and avoid predators or stalk their food.
One particular features that provides untold advantages to a select few species however, is the opposable thumb. The difference that such a small, specific feature can have is phenomenal. Without opposable thumbs, there would be no music or art. There would be no writing and as a result, there would probably be no complex language. That is just the tip of the iceberg.
Other than humans, there are not many animals with opposable thumbs, but there are some, and we take a look at a good selection of these below. As well as discussing what opposable thumbs are and the advantages that they provide.
What Does Having Opposable Thumbs Mean?
Having opposable thumbs means having a thumb which is capable of touching the tips of your other fingers on the same hand. This is an anatomically unique trait found only in a select few animals, and allows for increased grip strength and dexterity.
The Advantage Of Having Opposable Thumbs
Opposable thumbs allow us to grip objects such as tools and hold them securely, as well as perform tasks such as tying knots or manipulating small objects.
This trait has allowed us to construct and engineer, to manipulate complicated objects and devices, and even open and use containers like jars. It also allows us to create intricate art forms with our hands. Without opposable thumbs, humans would never have discovered how to set fires, or to cook food.
With other primates, marsupials and mammals lucky enough to have evolved with opposable thumbs, they provide dexterity, exceptional grip and manoeuvrability.
Opposable Vs Pseudo Opposable Thumbs
As mentioned above, opposable thumbs are those that can bend and curl around to touch the tips of the other fingers on the same hand. This is a unique trait found only in a select few animals, including humans and primates.
Pseudo opposable thumbs, on the other hand, are found in animals such as opossums, kangaroos, and raccoons, and are characterized by a digit that acts more like a thumb-like structure than a true thumb. This thumb-like structure is used for gripping and grasping objects, but is not quite as effective as a true opposable thumb.
There are a few animals that also have non-opposable thumbs which are different again. With non-opposable thumbs, the thumb can not be placed in opposition to the other digits on the same hand. None of the advantages of grip and control are present in hands with non-opposable thumbs.
Animals With Opposable Thumbs
Koalas are both nocturnal and are arboreal animals, which means they live in trees and are mostly active at night. They are found around many areas in Australia, particularly around Queensland, Victoria and New South Wales. They are very furry animals, that historically were mistaken as a type of bear even though they are an entirely different animal altogether. The fur on a koalas bottom is densely packed to provide a ‘cushion’ for the hard branches it sits upon.
Koalas limbs are long and they have large sharp claws to assist them with climbing trees. Koalas have 5 digits and are quite uniquely equipped with two opposable thumbs on each hand, which help them to grasp objects such as food and branches. Having two thumbs gives them exceptional grip strength when climbing in the eucalyptus trees, and moving from tree to tree.
Koalas are one of the few mammal species that actually have fingerprints. Koala fingerprints are similar to human fingerprints and it is quite difficult to tell them apart, even under a microscope.
The Great Apes
Most primates, but not all, have opposable thumbs similar but not identical to human thumbs. Some, particularly many of the new world monkeys, have pseudo-opposable thumbs, and there are one or two that have non-opposable thumbs. But many have opposable thumbs.
The great apes are an example of the latter, with all species having opposable thumbs in one form or another. There are even suggestions that some are more evolved than human thumbs, and some have opposable toes as well as thumbs.
Gorillas are the largest of the ‘Primates’ and are divided usually into the sub-species of Western Lowland Gorillas, Eastern Lowland Gorillas, and Mountain Gorillas. Unlike many other primates, gorillas tend to stick to the ground, with exception to females raising her young. Males grow into heavy animals, much more suited to a terrestrial rather than an arboreal environment. But that doesn’t mean they have less use for opposable thumbs.
Gorillas use these thumbs for greater control of tools, such as sticks and stones they use for a variety of tasks, from preparing or processing food. They prepare new ‘beds’ very often as they move around a lot. Their thumbs allow them to grab, and detach foliage and small branches, and to prepare adequate bedding with ease.
They also use their hands, including their opposable thumbs to perform different social interactions and cues. In captivity they have even been able to learn sign language!
As well as opposable thumbs, gorillas also have opposable big toes, something that we humans don’t have. They also have fingerprints.
Bonobos are probably the gentlest of the great apes. Their pacifist nature has led to these apes often being associated with the phrase ‘make love not war’. They were historically also known as ‘pygmy chimpanzees’ but are in fact a completely different species.
Though similar to chimpanzees, the bonobo is a smaller primate, and consists usually on a herbivorous diet.
These are the most social of the great apes, with really good bonding and networking behaviours. They love to groom and be around each other, and the play often. They are found in the lowland jungle and swamp forests mostly in the Democratic Republic of Congo.
Bonobos are known to use complex language and hand gestures, where different vocalizations or gestures can mean several different things, depending on the environment or present situation.
Orangutans are native to Indonesia and Malaysia, they are currently found only in rainforests on the islands of Borneo and Sumatra, though fossils have been found in Java, Vietnam and China.
They can be found in rainforests as well as other forests at higher elevations and near lowland swamps. They will sleep in trees as well as move through the trees in search of fruit ,and this is where their opposable thumbs come in very handy. They can move through the trees with ease, hang and swing, and pick fruit with little effort.
Orangutans are the most arboreal of the great apes, spending nearly all of their time in the trees. Every night they make nests, in which they sleep, from branches and foliage. They are more solitary than the other apes, with males and females generally coming together only to mate.
Some of the countries the chimpanzee is located in include Sierra Leone, Angola, Tanzania and Congo. These apes are also sometimes called the ‘rainforest chimpanzee’, or ‘common chimpanzee’. There are several recognized subspecies, but all of them are intelligent animals, with a complex behaviour and communication system.
The chimpanzee splits its time between the ground and up in the trees, but will usually sleep in a tree where it will build a nest for the night. They are very similar to Bonobos, though have a range of unique features.
Like all the great apes, the chimpanzee uses their opposable thumbs to control tools, more and grip objects and to communicate with gestures.
Interestingly, current research shows that chimpanzees, as well as all great apes, share sign language similar to us humans. There is an overlap of around 95% of the gestures they use, across the species. They have specific gestures to communicate the desire to mate, to request another individual to come closer, or to request another individual groom them, as well as many others. This seems to suggest that in the past, a historic ancestor that links todays primate species, may have developed these language skills.
Old World Monkeys
There are a few features, other than location, that separate new world monkeys from old world monkeys. The tail is a common features that differentiates often between the types, but so are opposable thumbs. Many old world monkeys have opposable thumbs, but it is much more rare in new world monkeys. Here are some of the old world species that have these thumbs.
There are six distinct species of baboon, and each has its own native territory in different areas of Africa, with one residing in the Arabian Peninsula. All species have opposable thumbs, which they use for climbing, grabbing and controlling objects. They also have an opposable toe on each foot too.
Baboons are both diurnal and terrestrial rather than arboreal, but they do sleep in the trees, for safety away from predators. They are the largest of all the monkeys, old world and new world.
Baboons are omnivores, eating a variety of seeds and foliage, as well as some shellfish where available, small rodents and birds, and even small monkeys such as vervets when the opportunity arises.
Grivet monkeys are found only in sub-Saharan Africa. They are part of the vervet monkey group, and their range extends from Senegal and Ethiopia down to South Africa.
Grivet monkeys inhabit forests, woodlands and savannas near rivers and streams. They spend most of their time in the trees.
The first digit on their hands and feet are opposable allowing the Vervet monkeys to grab hold of objects. Their hands are used for moving, feeding and grooming. The hind legs are especially strong for leaping across branches. Their long tails are not prehensile, but are used for balance, steering and braking while leaping from branch to branch.
the Rhesus Macaque is both arboreal and terrestrial, and is mostly active during the day (diurnal). These are intelligent monkeys, and quite uniquely they love to swim. They are very proficient at this and love to swim in groups. They use their opposable thumbs similarly to their other old world cousins, and are a very social species, living in groups of between 20 – 200.
While all of the great apes have opposable thumbs, it is more rare with the lesser apes. There are some though that have this feature, and one such example are Gibbons.
Gibbons are primates in the family ‘Hylobatidae’. They are known as lesser apes, which differ from great apes (chimpanzees, gorillas, orangutans and humans) in many ways. These include being smaller and pair-bonded, in not making nests, and in certain anatomical details in which they superficially more closely resemble monkeys than great apes do.
Gibbons have lean bodies which are specially adapted to swing below the branches suspended by their arms. They hook their fingers over a branch, not actually grabbing it, and sometimes make long swings and let go of the branches entirely.
Waxy Monkey Leaf Frog
The Waxy Monkey Leaf Frog (Phyllomedusa sauvagii) is a relatively recent discovery, and is one of the few species of frog that have opposable thumbs. They are also known as Waxy Monkey Tree Frogs, and are found across South America, particularly in Argentina, Bolivia, Paraguay and Brazil. They get their name because they spend much of their time in the trees.
They might not have big hands like primates, but they are able to use their opposable thumbs all the same, for grabbing and climbing branches. These little frogs have a very ‘other-worldly’ look to them. They lay their eggs on a leaf that is suspended by a branch over a source of water. This is necessary so that when they hatch, the tadpoles are instantly transported to water to develop further from their larval stage.
From the minute they are born, baby chameleons are equipped to give life a go. They are immediately able to eat flies and insects, and don’t require any nursing at all. They can walk and scurry as soon as they have dug themselves out if their buried nest.
As soon as they are born, they quickly find their way to the trees, and away from any potential ground predators. And in the trees is where they will spend most of their arboreal lives. They are aided for life in the trees with both prehensile tails which they can use like an extra limb and for balance, as well as opposable digits on all four of their limbs.
On their front limbs, they have three digits that extend forward, and two that extend to the outside to create a ‘grippable’ appendage. On their rear limbs these positions are reversed, with two digits extending forward, and three to the outside.
Animals With Pseudo Opposable Thumbs
Lemurs are found only on the island of Madagascar and the Comoros Islands off of the East Coast of Africa.
The Lemur has hind limbs longer than their forelimbs and the palms and soles are padded with soft, leathery skin. Their fingers are slender and semi-dexterous (semi-skillful) with flat, human-like nails. Although their thumbs are not as fully dexterous as true opposable thumbs, they can still use them for grasping branches and manipulating food. They are just not as effective or nimble as opposable thumbs.
Lemurs have one claw, known as a ‘toilet claw’ (a comb-like claw), on the second toe of each hind limb specialized for grooming purposes.
These animals are diurnal and inhabits both the ground and the trees. They form troops of up to 25 individuals and social hierarchies are determined by sex.
There are two species of Loris, and both are small, nocturnal prosimians native to the rainforests of Sri Lanka and Southern India.
They have two large, closely set, saucer-like brown eyes that are used for precise depth perception and they are surrounded by dark-brown to black circles of fur. They have large prominent ears, which are thin, rounded and hairless at the edges. A major difference between the gray and red slender loris lies in their ear shape.
They have strong fingers and toes which are capable of maintaining a powerful grip for astonishingly long periods of time. The second digit on the hand and foot are very short, which allows for gripping on branches and food. They also have small finger nails.
The slender loris has a 4 way grip on each foot. The big toe opposes the other 4 toes for a pseudo-opposable, pincer-like grip on branches and food.
The Giant Panda is native to central-western and southwestern China and is one of the rarest mammals in the world. They are a member of the bear family, Ursidae and are easily recognized by their large, distinctive black patches around the eyes, over the ears and across their round body.
Many people find these cuddly looking bears to be lovable, however, giant pandas can be as dangerous as any other bear. They have the largest molars out of all the carnivorous mammals.
The forepaws of the giant panda have an extra opposable pseudo thumb which is used in conjunction with its forefingers and enables the panda to grasp even small bamboo shoots with precision.
Unlike opposable thumbs that include distal and proximal phalange bones, the panda’s pseudo opposable thumb is an enlarged carpal bone which is one of the bones that usually make up the wrist.
Opossums generally referred to as ‘Didelphimorpias’ are small marsupials that are found in different regions across the Americas, particularly South America, depending on the species. Only one species can be found in North America, and is the only marsupial to be found there.
They are nocturnal by nature, and may often be found at night hanging by their prehensile tail upside down from branches or beams. They also develop very sharp claws, and opposable thumbs or ‘big toes’ on their hind feet which also make them exceptional climbers. These traits help young opossums find safety in the trees once they are no longer welcome in the safety of their mothers pouch or on her back.
Possums are often mistaken for opossums, and while both animals may look similar, and while they are both marsupials, they are entirely different species from different genera. They also live worlds apart, with Possums being native to Australia, New Guinea, and Sulawesi.
Possums also have furry tails and are smaller than the bare tailed opossums. They also belong to different taxonomical orders. One of the things they do have in common though, is their pseudo-opposable thumbs. All possums with exception of two species, have pseudo-opposable thumbs. On their front limbs, two of their toes are in opposition to the other three, and on their rear limbs they have an opposable ‘big toe’ too.