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The mammals (Mamalia) are a class of animals that have managed to diversify by all means (land, sea and air) thanks to the many adaptations they have acquired throughout evolution. In addition to land representatives (typical of mammals), there are some mammals capable of flying, such as bats, and of living in the aquatic environment, the so-called marine mammals, such as dolphins and whales.
Within mammals, we are also humans, and specifically we are the only member of the genus Homo (family Hominids). In Green Ecologist we reveal some of the general characteristics of land mammals.
Mammals and their origin
The term mammal comes from the Latin 'mamma’, Which in Spanish means tit or breast, and the suffix‘fero', Whose meaning refers to carrying it or carrying it. Thus, the meaning of the word mammal refers to ‘that carries breasts’, that is, it identifies those animals that in their first days of life feed on breast milk through mammary glands.
Mammals are a more evolved group of animals than other groups. Its origin is about 245 million years. Back then, they still didn't look like they do today, but were small insectivorous animals that descended from therapsid reptiles of the Triassic period. After the disappearance of the dinosaurs, during the Cretaceous period, mammals began to evolve and occupy their ecological niches. For this reason, mammals are considered to have a common ancestor, that is, it is a monophyletic group.
Main characteristics of land mammals
Between the general characteristics of land mammals, which are what differentiate them from other groups of animals, stand out:
- They have a synapsid skull (skull with a hole behind the eye sockets) with a head that remains attached to the trunk through the neck. They also have a spine as the central axis of the body.
- Brain volume greater than other groups of animals, i.e. a bigger brain than that of other types of living beings. This trait allows them to acquire greater psychic abilities and incredible learning faculties.
- Presence of waists on your limbs, which allow them to lift the body off the ground.
- Presence of a mouth composed of lips and teeth. In certain cases, such as platypus, the teeth only appear during the juvenile period.
- Body covered with hair, although in some cases the hair is little or no and the skin acts as insulation.
- Presence of glands with specific functions in the deep layers of the skin. Among these are the mammary glands (they produce milk to feed the young), sweat glands (they facilitate the cooling of the body and develop excretory functions), odoriferous glands (transmit signals) or sebaceous glands (provide protection to the hair).
- Presence of four limbs that allow them to stand, on all fours or on two legs, and move in the terrestrial environment.
- Ability to maintain a constant body temperature thanks to their diet and regardless of the environmental temperature (homeothermic animals).
- Breathing through lungs. Thanks to the diaphragm and its contraction movements, the air gets into the lungs.
- Presence of a four-chambered heart (two atria and two ventricles) and a double, closed and complete circulatory system.
- Most mammals have auditory appendages or ears or pinna, even mobile in many species.
How Mammalian Animals Reproduce
Regarding their reproduction, terrestrial mammals present another distinctive characteristic, such as the viviparous reproduction. In this type of reproduction, the embryo develops inside the mother's womb and the individuals possess internal reproduction, that is to say, the ovule produced by the female is fertilized thanks to a copulatory organ in the males. There are some exceptions to the viviparous reproduction of mammals, one of them is the monotremes (platypuses and echidnas), which lay eggs, although once hatched the young feed on milk through the mother's mammary glands.
The order of Marsupials is intermediate between viviparous and Monotreme mammals, since the young are born prematurely and cling to their parent's nipple, inside an abdominal pouch or pouch (absent in some species).
Reading this other article by Ecologist Verde you can expand this information and know all about Are mammalian animals oviparous or viviparous?
Feeding of mammalian animals
Finally, to finish talking about the general characteristics of mammalian animals, we want to inform you about their diet.
The feeding in terrestrial mammals it is very varied between species, being able to be carnivorous, herbivorous, omnivorous or, even, insectivorous. The ability to have different types of diet is proof of its greater evolution compared to other groups. Also, depending on your eating habits, your digestive system undergoes different adaptations.
If you want to read more articles similar to General characteristics of land mammals, we recommend that you enter our category of Animal Curiosities.
