mammals
Mammals are an important group of vertebrates characterized by the presence of mothers feeding their offspring. Notable characteristics of mammals include lactation, body hair, endothermy (warm-blooded animals), and a four-chambered heart. There are many species of mammals, living in almost all ecosystems on Earth, from the deep sea to the mountains, from tropical rainforests to the cold polar regions.
scientific name：Mammalia
Features：
suckle：Females have mammary glands that secrete milk to feed their young.
Body hair：Most mammals are covered with hair.
Endothermic：Maintaining a constant body temperature through metabolism.
Four-chambered heart：Mammals have four-chambered hearts to ensure efficient oxygen delivery.
viviparous：Most mammals reproduce by giving birth to live young, but some species, such as monotremes (e.g. the platypus), lay eggs.
Habitat：Almost all habitats on Earth, including land, ocean, fresh water, polar regions, etc.
Mammal classification table
Mammals are numerous and can be subdivided based on different biological characteristics. Mammals are roughly divided into three subclasses:
Monotremata: Oviparous mammals.
Marsupialia: Kangaroos, koalas, etc., whose young continue to develop in a pouch outside the mother's body.
Eutheria: Viviparous mammals, the most abundant species, including humans, lions, whales, etc.
The following is a detailed classification table of mammals, including all orders, families, genera and typical animals:
| sort | Order | Family | Genus | Examples |
| Monotremata | Monotremata | Ornithorhynchidae | Ornithorhynchus | Platypus, Echidna |
|
| Tachyglossidae | Echidna | Echidna |
| Marsupialia | Marsupialia | Macropodidae | Macropus | Kangaroos, wombats, possums |
|
| Phascolarctidae | Phascolarctos | koala |
|
| Dasyuridae | Dasyurus | Bandicoot, Tasmanian devil |
| Eutheria | Carnivora | Canidae | Canis | Wolf, dog, fox |
|
| Felidae | Felis | House cat, lion, tiger |
|
| Ursidae | Ursus | Black bear, brown bear, polar bear |
| Perissodactyla | Equidae | Equus | Horse, donkey, zebra |
|
| Rhinocerotidae | Rhinoceros | White rhino, black rhino |
|
| Tapiridae | Tapirus | Tapirus |
| Artiodactyla | Bovidae | Bos | Cattle, antelopes, sheep |
|
| Cervidae | Cervus | Deer, reindeer, sika deer |
|
| Suidae | Sus | Wild boar, domestic pig |
| Cetacea | Balaenidae | Megaptera | Humpback whale, blue whale |
|
| Delphinidae | Delphinus | Dolphins, killer whales |
| Primates | Cercopithecidae | Pongo | Orangutans, gibbons, monkeys |
|
| Hominidae | Homo | Humans, chimpanzees, orangutans |
| Rodentia | Sciuridae | Sciurus | Squirrels, Ground Squirrels |
|
| Castoridae | Castor | beaver |
|
| Muridae | Mus | House mouse, vole |
| Chiroptera | Vespertilionidae | Myotis | Small bat, big bat |
| Lagomorpha | Leporidae | Oryctolagus | Rabbit, hare |
Characteristics and Adaptations of Mammals
Mammals are one of the most diverse groups in the biological world. Here are the main characteristics of mammals and how they adapt:
1. Breastfeeding
A notable feature of mammals is that mothers secrete milk through their mammary glands to feed their offspring. This allows mammal cubs to receive adequate nutritional support after birth, increasing their survival rate.
2. Body hair
Almost all mammals have body hair, which not only helps to keep warm, but also plays a camouflage or display function in some species. For example, the white hair of polar bears helps them camouflage in the snow and reduce the risk of being discovered by prey.
3. Homeothermy
Mammals maintain a stable body temperature through metabolism, which allows mammals to maintain a suitable temperature regardless of changes in the outside temperature. This feature allows mammals to survive in a variety of environments, including extreme environments such as polar regions and deserts.
4. Viviparity
Most mammals reproduce by giving birth to live young, which allows the embryo to receive more stable nutritional support in the mother's body and be more viable after birth. Some species, such as kangaroos and koalas, adopt marsupial parenting.
5. Diet
Mammals have a variety of diets, from herbivorous to carnivorous and omnivorous. Some species (such as bats) have even evolved to suck blood. Different diets allow mammals to find living space in a variety of ecological environments.
Summary: Mammals are the most advanced animals with the most perfect physiological functions. There are more than 4,000 existing mammals. Almost all mammals are warm-blooded. Feeding their offspring with breast milk is one of their most notable characteristics. Mammals include nearly 30 orders, including Monotremes, Carnivores, Primates, Perissodactyla, and Artiodactyla.
