Bipedal Animals - Examples and Characteristics

Author: Peter Berry
Date Of Creation: 13 February 2021
Update Date: 12 November 2024
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CARTA: The Upright Ape: Bipedalism and Human Origins - Running, Walking and Evolution
Video: CARTA: The Upright Ape: Bipedalism and Human Origins - Running, Walking and Evolution

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When we talk about bipedalism or bipedalism, we immediately think of the human being, and we often forget that there are other animals that move in this way. On the one hand, there are the apes, the animals that are evolutionarily closer to our species, but the reality is that there are other bipedal animals that are not related to each other, nor to humans. Do you want to know what they are?

In this article by PeritoAnimal, we will tell you what are bipedal animals, how were their origins, what characteristics they share, some examples and other curiosities.

What are bipedal animals - Features

Animals can be classified in several ways, one of which is based on their mode of locomotion. In the case of land animals, they can move from one place to another by flying, crawling or using their legs. Biped animals are those that use only two of their legs to move around. Throughout evolutionary history, numerous species, including mammals, birds and reptiles, have evolved to adopt this form of locomotion, including dinosaurs and humans.


Bipedalism can be used when walking, running or jumping.Different species of bipedal animals may have this form of locomotion as their only possibility, or they may use it in specific cases.

Difference between bipedal and quadrupedal animals

the quadrupeds are those animals that move using four limbs locomotives, while bipeds move using only their two hind limbs. In the case of terrestrial vertebrates, all are tetrapods, that is, their common ancestor had four locomotor limbs. However, in some groups of tetrapods, such as birds, two of their members underwent evolutionary modifications and this resulted in bipedal locomotion.

The main differences between bipeds and quadrupeds are based on the extensor and flexor muscles of their limbs. In quadrupeds, the mass of the leg flexor muscles is almost twice that of the extensor muscles. In bipeds, this situation is reversed, facilitating upright posture.


Bipedal locomotion has several advantages in relation to quadrupedal locomotion. On the one hand, it increases the visual field, which allows bipedal animals to detect dangers or possible prey in advance. On the other hand, it allows the release of the forelegs, leaving them available to perform different maneuvers. Finally, this type of locomotion involves an upright posture, which allows for greater expansion of the lungs and rib cage when running or jumping, generating greater oxygen consumption.

Origins and evolution of bipedism

Locomotor limbs evolved convergingly into two large groups of animals: arthropods and tetrapods. Among tetrapods, the quadruped condition is the most common. However, bipedal locomotion, in turn, also appeared more than once in animal evolution, in different groups, and not necessarily in a related way. This type of locomotion is present in primates, dinosaurs, birds, jumping marsupials, jumping mammals, insects and lizards.


There are three causes considered as the main responsible for the appearance of bipedism and, consequently, of bipedal animals:

  • The need for speed.
  • The advantage of having two free members.
  • Adaptation to flight.

As speed increases, the size of the hind limbs tends to increase compared to the forelegs, causing the steps produced by the hind limbs to be longer than the forelegs. In this sense, at high speeds, the front limbs can even become an obstacle to speed.

biped dinosaurs

In the case of dinosaurs, it is believed that the common character is bipedalism, and that quadrupedal locomotion later reappeared in some of the species. All tetrapods, the group to which predatory dinosaurs and birds belong, were bipedal. In this way, we can say that dinosaurs were the first bipedal animals.

Evolution of bipedism

Bipedism also appeared on an optional basis in some lizards. In these species, the movement produced by the elevation of the head and trunk is a consequence of the forward acceleration combined with the retreat of the body's center of mass, due, for example, to the elongation of the tail.

On the other hand, it is believed that among primates bipedism appeared 11.6 million years ago as an adaptation to life in trees. According to this theory, this characteristic would have arisen in the species. Danuvius Guggenmosi that, unlike the orangutans and gibbons, which use their arms a lot for locomotion, they had hind limbs that were kept straight and were their main locomotor structure.

Finally, jumping is a fast and energy-efficient mode of locomotion, and it has appeared more than once among mammals, linked to bipedalism. Jumping over large hind limbs provides an energy advantage through the storage of elastic energy potential.

For all these reasons, bipedalism and upright posture emerged as a form of evolution in certain species to ensure their survival.

Examples of bipedal animals and their characteristics

After reviewing the definition of bipedal animals, seeing the differences with quadrupedal animals and how this form of locomotion came about, it's time to know some of the prominent examples of bipedal animals:

Human being (homo sapiens)

In the case of humans, it is believed that bipedism was selected mainly as an adaptation to totally free hands to get food. With hands free, the behavior of creating tools became possible.

The human body, totally vertical and with totally bipedal locomotion, underwent abrupt evolutionary renovations until reaching its current condition. The feet are no longer parts of the body that can be manipulated and become totally stable structures. This happened from the fusion of some bones, changes in the proportions of size of others and the appearance of muscles and tendons. In addition, the pelvis was enlarged and the knees and ankles aligned below the body's center of gravity. On the other hand, the knee joints were able to rotate and lock completely, allowing the legs to remain erect for long periods of time without causing too much tension in the postural muscles. Finally, the chest shortened from front to back and widened to the sides.

Jumping Hare (capensis pedestal)

this furry 40 cm long rodent it has a tail and long ears, characteristics that remind us of hares, although it is not actually related to them. His forelegs are very short, but his hindquarters are long and stout, and he moves in heels. In case of trouble, he can cross between two and three meters in a single jump.

Red kangaroo (Macropus rufus)

It's the biggest marsupial existing and another example of a bipedal animal. These animals are not able to move about walking, and can only do so by jumping. They perform the jumps using both hind legs at the same time, and can reach a speed of up to 50 km/h.

Eudibamus cursoris

It's the first reptile in which bipedal locomotion was observed. It is now extinct, but it lived in the late Paleozoic. It was about 25 cm long and walked on the tips of its hind limbs.

Basilisk (Basiliscus Basiliscus)

Some lizards, such as the basilisk, have developed the ability to use bipedalism in times of need (optional bipedalism). In these species, morphological changes are subtle. the body of these animals continues to maintain a horizontal and quadrupedal balance. Among lizards, bipedal locomotion is mainly performed when they are moving towards a small object and it is advantageous to have a wide visual field, rather than when directed towards an object that is very wide and which it is not necessary to keep in sight. .

O Basiliscus Basiliscus it is able to run using only its hind legs and reach speeds so high that it allows it to run in water without sinking.

Ostrich (Struthio camelus)

this bird is the fastest biped animal in the world, reaching up to 70 km/h. Not only is it the biggest bird there is, it also has the longest legs for its size and has the longest stride length when running: 5 meters. The large size of its legs in proportion to its body, and the disposition of its bones, muscles and tendons, are the characteristics that generate in this animal a long stride and a high stride frequency, resulting in its high maximum speed.

Magellanic penguin (Spheniscus magellanicus)

This bird has interdigital membranes on its feet, and its terrestrial locomotion is slow and inefficient. However, its body morphology has a hydrodynamic design, reaching up to 45 km/h when swimming.

American cockroach (american periplanet)

The American cockroach is an insect and therefore has six legs (belongs to the Hexapoda group). This species is specially adapted for locomotion at high speed, and has developed an ability to move on two legs, reaching a speed of 1.3m/s, which is equivalent to 40 times its body length per second.

This species has been found to have different locomotion patterns depending on how fast it is moving. At low speeds, he uses a tripod gear, using three of his legs. At high speeds (greater than 1 m/s), it runs with the body raised from the ground, and with the front raised in relation to the rear. In this posture, your body is mainly driven by the long hind legs.

other biped animals

As we said, there are many animals that walk on two legs, and below we show a list with more examples:

  • meerkats
  • chimpanzees
  • chickens
  • penguins
  • Ducks
  • kangaroos
  • gorillas
  • baboons
  • Gibbons

If you want to read more articles similar to Bipedal Animals - Examples and Characteristics, we recommend that you enter our Curiosities section of the animal world.