Mammals (Meaning and Explanation)

We explain what mammals are and what their main characteristics are. Also, the types of mammals and some examples.

Mammals - lions — Mammals date back approximately 200 million years.

What are mammals?

Mammals are known as vertebrate and warm-blooded animals belonging to the class mammalia whose essential characteristic is that females have mammary glands that are used to generate milk to feed their young. There are some 5,486 current species of mammals known, including humans themselves, and most of them are all viviparous, except for monotremes (such as the platypus).

the mammals They date back approximately 200 million years from some common ancestor derived from synapsid or mammalian reptiles, which emerged during the Triassic Period. But unlike reptiles, they have the ability to regulate body temperature, which may have been key to their survival from the K-Pg (Cretaceous-Paleogene) Mass Extinction Event that wiped out non-avian dinosaurs.

Mammal characteristics

Mammals - human being — All female mammals have mammary glands.

Mammals are an extremely diverse and numerous group of animals, of the most and best studied by humans among the entire animal kingdom. The morphological diversity of its animal members is such that they serve as examples from a blue whale, a giraffe and a kangaroo, to a dog, a platypus or the human being himself.

However, all mammal species share certain minimal characteristics, such as:

Presence of mammary glands Located in the body of the female of the species, with which they secrete milk and breastfeed their young.
Mandible composed of a dental bone Instead of several bones or moving parts. In addition, the mandible articulates with the skull between the dentary and the squamosal.
have an ear with three bones Known as an incus, hammer and stirrup, with the exception of monotremes (which have reptilian hearing).
have hair in almost all stages of their life And all species have it to some extent.
can regulate body heat Through sweating, tremors and other ways to preserve homeostasis without resorting to external elements.

Types of mammals

Mammals - kangaroo — Marsupials carry their newborn offspring in a skin sac known as a marsupium.

A first classification of mammals is given by distinguishing between the ways in which their offspring are formed, as follows:

Monotremes Those few species of mammals whose females lay eggs after being fertilized. This is the oldest evolutionary group of the group.
Marsupials These species (around 300) of mammals give birth to their young after a short gestation period, after which they must climb through the mother's skin until they enter a skin sac known as a marsupium, within which they will be protected and have access to breasts. After several months, when they are fully formed, they will leave the pouch to begin their independent life.
Placentaries Most mammal species belong to this category, characterized by gestating their young for several months and then giving birth to them when they are ready to lead an independent life. In the case of humans, however, babies are born in a high state of defenselessness that requires almost complete care during their first years of life.

Marine and terrestrial mammals

Mammals - dolphin — Aquatic mammals maintain lung respiration and suckling.

Although mammals emerged evolutionarily as a terrestrial species, and the vast majority lead a continental life, they also There have been cases of certain terrestrial species that have returned to the aquatic habitat adapting his body in the process to swimming. Thus, they have changed legs for fins, mutated the type of coat and altered the proportions of fat on their body to conserve heat, although in the process they have not lost lung breathing, breastfeeding, or other characteristic physical features.

However, there are no flying mammals, with the exception of the bat.

Examples of mammals

Mammals - bat — The bat is the only genus of flying mammals.

Examples of mammals abound in everyday life and in other natural environments:

The human being himself As well as primates and apes in their entirety.
All dogs and canids From our common pets, to wolves, jackals and hyenas.
All felines From cats to lions, panthers, tigers, etc.
Milking animals Like sheep, cows or goats.
Aquatic mammals. Like the dolphin, the blue whale, the sea lion, the seals or the manatees.
The large African and American ruminants Like rhinos, giraffes, buffaloes, etc.
The bats Only genus of flying mammals.