The land animals They are those that spend most of their life cycle on earth and belong to various groups that evolved independently. These animals developed adaptations to be able to survive in the terrestrial environment, very different from the aquatic environment..
First, they travel on a solid medium with air surrounding them. Air is less dense than water, therefore terrestrial animals are forced to support their own weight due to a greater effect of the force of gravity..
Therefore, they have developed adaptations that allow them to survive in different terrestrial habitats. For example, a suitable body structure (internal or external skeleton, muscles) and ways of moving according to this new condition (legs, crawling systems).
Additionally, oxygen, which is a fundamental element for life in the terrestrial environment, is dissolved in the air. Therefore, terrestrial animals have lungs, tracheas and other variants to be able to use it in their vital functions.
Terrestrial animals have in common having developed adaptation strategies to be able to survive in the terrestrial environment. These adaptations are due to the need to respond to the challenges posed by the properties of the terrestrial environment in comparison with the aquatic environment..
Life arose in water, which implied evolving in an environment where there is a certain weightlessness (the density of water allows it to float). On the other hand, oxygen is dissolved in the water, in addition to maintaining a more uniform temperature as well as the availability of humidity..
In the terrestrial environment, animals are subjected to a greater action of gravity on their body. Likewise, they are surrounded by a gaseous medium, with a higher incidence of solar radiation..
Another problem present in the terrestrial environment is the variation of temperature in its various habitats, product of the higher incidence of solar radiation. As well as the fact that the earth heats up and cools faster than water.
Under these conditions, terrestrial animals must develop different adaptations to survive in dry or very humid, hot and cold habitats. A good example is the polar bear, with a black skin covered with translucent hairs and underneath it a layer of fat..
Black skin absorbs heat, oil maintains heat and moisture, and translucent hairs reflect light making it white. The latter as camouflage in the snow to more easily hunt their prey.
An environmental challenge that terrestrial animals face is the reduced availability of water, mainly due to the loss of water through evapotranspiration. Therefore, terrestrial animals have developed systems to regulate their perspiration such as skins, fur and other mechanisms to avoid excessive water losses..
The air that surrounds the terrestrial animal is not very dense, unlike the aquatic environment, so it must support the body itself. This forced terrestrial species to develop body structures to stand up and move..
Such as solid internal skeletons on the part of vertebrates such as mammals, birds and reptiles. As well as exoskeletons adapted to the conditions of the terrestrial environment surrounded by air and not water in insects.
Terrestrial animals must move and for this various forms of locomotion were developed such as walking on legs such as birds (2), mammals and reptiles (4), insects (6) and arachnids (8). Other mechanisms linked to the formation of legs is jumping, as in the grasshopper or the kangaroo.
Crawling locomotion is also used, where specialized muscles drive the body without legs at ground level (snakes, worms).
Finally, a characteristic of terrestrial animals is the diversity of habitats they occupy, with respect to the aquatic environment. Terrestrial animals face hot or cold deserts, different types of jungles and forests, as well as savannas and grasslands.
Terrestrial animals face the need to obtain oxygen from the air and for this they have developed various adaptations. 4 basic respiratory systems are presented: pulmonary, book lungs, trachea-based and cutaneous respiration.
The pulmonary system focuses on the lungs, a pair of specialized tissue sacs that are fed by air through a tube (trachea). There, in the alveoli there is gas exchange between air and blood, extracting COtwo and providing oxygen that goes to cells, occurring in mammals, reptiles and birds.
Some arachnids have a system called book lungs, which consists of a series of tissue folds where gas exchange also occurs. Another group of arachnids, insects and myriapods use the trachea system (branched tubes open to the outside through holes called stigmas that are throughout the body).
Finally, cutaneous respiration by diffusion, that is, a thin skin that allows gas exchange, occurs in annelids.
The most accurate way to classify land animals is according to the different taxonomic groups that zoology has established. Thus, there are annelids, onychophores, insects, arachnids, myriapods, crustaceans, reptiles, birds and mammals.
They are earthworms, small cylindrical worms that live in the soil, processing the earth to obtain the organic matter that is their food. These organisms breathe by diffusion through their thin skin.
They are soft-bodied animals discovered or protected by a shell, most of their species are aquatic, but many snails and slugs are terrestrial.
This group includes animals that complete their life cycle between land and water. Being some of its species mainly terrestrial such as toads, and others mainly aquatic such as frogs and salamanders.
This is one of the most diverse and numerous animal groups on the planet, with the vast majority of its terrestrial species, except for a few that are aquatic and others eminently aerial. To adapt to this environment they have developed an exoskeleton or external skeleton formed by a hard substance called chitin..
This exoskeleton protects them both from desiccation due to their wax coating, and from predators. They move by six legs, some species have strong hind legs to make great leaps and in some cases they also have wings.
Like insects, arachnids (spiders, scorpions) have exoskeletons and move on legs, in this case 4 pairs. Their breathing can be through tracheae or through the so-called book lungs..
This group includes centipedes, millipedes and other similar organisms, which are characterized by having a head and a segmented trunk with multiple pairs of legs. These animals need to be protected from desiccation, since they lack the wax layer that covers the exoskeleton of insects.
Most are aquatic, but there are terrestrial and intermediate ones, reaching some 67,000 species in total and are characterized by having two pairs of antennas. Among the terrestrial and intermediate, there are some species of crabs that have five pairs of legs, two of which are transformed into claws..
The so-called land crabs belong to the gecarcinidae family and require visiting the sea to reproduce..
This group includes snakes, lizards, crocodiles, alligators and others, characterized by having a scaly skin and being ectothermic (they control their temperature by placing themselves in the Sun to increase it or in the shade or in the water to decrease it). This group moves on all fours or crawls with undulating movements of their abdominal muscles and scales..
Birds develop much of their life in the air and perched in trees, which in a sense makes them land animals. However, some prefer to classify them as airborne animals..
There are birds whose environment is totally or fundamentally terrestrial, such as the ostrich, the rhea, the hen, the turkey and many others. This group of animals move on two legs (bipedal) and have feathers covering their skin to regulate their temperature..
Mammals evolved on land and most of their species continue to inhabit it, although a few returned to the aquatic environment. The human being and the rest of the primates, such as monkeys, gorillas, chimpanzees, orangutans, are in the group of exclusively terrestrial mammals.
Also the felines, including the tiger, the jaguar, the lion, the lynx and many other species. In addition to bears, the elephant, the giraffe, and domesticated species such as the dog, the cow, the pig and the horse.
They move by means of four legs in most cases (quadrupeds), or partially in two aided by the front limbs or hands (primates) or in two as is the case in humans. They breathe through lungs and regulate their temperature internally through the use of energy and inhabit almost all terrestrial ecosystems..
It is the pet par excellence in most of the world, being a terrestrial mammal diversified in numerous races by human manipulation. Unlike its wild relatives, the dog is adapted to living in human environments, although it can become feral.
One of the most emblematic land animals is the lion, a mammal that is the greatest predator of the African savannah. It is a carnivorous animal, adapted to a warm seasonal habitat with little vegetation..
There are 3 species of elephants of two different genera, being the largest land animal that exists. They live in herds both in the savannas and in the jungles of Africa (Loxodonta africana Y Loxodonta cyclotis) and Asia (Elephas maximus) and are herbivores.
They are reptiles whose form of locomotion is creeping, crawling thanks to a very strong muscular system in their abdomen. It is a predator, feeding primarily on rodents, birds, and other small to medium-sized animals..
They belong to the group of insects and there are about 10,000 species of ants worldwide. They are animals that form large colonies with hierarchies such as soldiers, workers and a queen, being exclusively terrestrial and appearing in almost all habitats.
It is a running bird, so it has a pair of strong legs and reaches up to 3 m in height, being the largest bird in the world. They inhabit the African savannas and build their nests on the ground and reach speeds of up to 90 km / H.
They are omnivorous (they eat both vegetables and small animals and carrion), and their eggs can weigh up to 2 kg.
It is the largest marsupial that exists, reaching up to 1.5 m in height and 85 kg in weight, with two powerful hind legs. Their young complete their development in the bag of skin or pouch that the mother carries in her abdomen and move with great leaps that allow them to reach speeds of up to 70 km / h..
It is a myriapod that can reach up to 30 cm long, with a body with 23 red and black segments. On the front they have a pair of pincer-like legs (calipers) that inject toxic poison into humans and are predators of insects, arachnids, lizards, rodents and bats..
It is a land turtle that inhabits the savannas and jungles of tropical America, and has a black shell with pentagonal designs and yellow spots. The scales on its legs are red on a black background and the plates on its head are yellow, it is herbivorous and scavenger, as well as being used as pets..
There are 2 species of chimpanzees, the common (Pan troglodytes) and the bonobo or pygmy chimpanzee (Paniscus bread). They are the closest evolutionary animal species to us and inhabit the jungles of West Africa.
Many land animals have become extinct and others are currently threatened with extinction. The International Union for Conservation of Nature (IUCN) centralizes the red lists worldwide.
These lists list the species that are considered with some degree of threat of extinction, assigning them the corresponding category.
The panda bear is the emblem of the World Wide Fund for Nature (WWF for its acronym in English) and is a world reference for conservation. This animal inhabits the mountains of central China, there is only a population of 2,000 to 3,000 individuals left and according to the IUCN it is a species vulnerable to extinction.
This subspecies of gorilla lives in the mountains of Central Africa, between Uganda, Rwanda and the Congo, leaving only two populations with about 900 individuals. According to the IUCN the mountain gorilla is an endangered species.
This large bear inhabits the regions of the Arctic Circle and although it is a land animal, it is also a skilled swimmer. It is a quadruped predator of seals, reindeer and other arctic animals. According to the IUCN, the polar bear is a species vulnerable to extinction.
This small feline is endemic to the Iberian Peninsula, leaving only three populations (two in Andalusia with about 300 individuals and a very small one in the Montes de Toledo with 15 individuals. It is the most threatened feline in the world and according to the IUCN is an endangered species.
Of this particular white rhino subspecies, only two female specimens remain in a reserve in Kenya. According to the IUCN, the northern white rhino is a critically endangered species.