2024年11月27日 · An animal is considered a mammal if it can produce milk. Other features unique to mammals include hair or fur (chemically different from hairlike structures on non-mammals); the malleus, incus, and stapes in the ear; and a diaphragm separating the heart and lungs from the abdomen.

Mammal, (class Mammalia), any member of the group of vertebrate animals in which the young are nourished with milk from special mammary glands of the mother. In addition to these characteristic milk glands,...

Mammals include a wide variety of animals, from cats to humans to whales. There are more than 5,000 species, or kinds, of living mammal. More than half of all mammals are rodents , a group that includes mice and squirrels.

A mammal is an animal that breathes air, has a backbone, and grows hair at some point during its life. All female mammals have glands that can produce milk. The mother feeds the young with this milk until the young are old enough to get food for themselves.

2024年11月27日 · Mammal - Evolution, Classification, Adaptations: Mammals were derived during the Triassic Period from therapsids. Many of the attributes that evolved are correlated with their highly active habits—for example, efficient circulation with a four-chambered heart, hair for insulation, endothermy (warm-bloodedness), and improved mechanics in ...

How are mammals distinct from other animals? Why is the platypus a mammal? What is a marsupial? Where do marsupials live? How do marsupial pouches work?

mammal, Any member of the class (Mammalia) of warm-blooded vertebrates having four limbs (except for some aquatic species) and distinguished from other chordate classes by the female’s milk-secreting glands and the presence of hair at some stage of development.

Despite their size differences, the great blue whale and the pygmy shrew have something in common: they are both members of a warm-blooded, air-breathing class of vertebrate (backboned) animals known as Mammalia, or mammals. In many ways mammals are the most highly developed of all creatures.

Many species of animals, including mammals, fish, birds, and insects, migrate to specific areas to breed. A notable example is the migration of Pacific salmon, which leave the ocean and swim up fast-flowing rivers to freshwater spawning areas.

2024年11月27日 · Mammal - Adaptations, Physiology, Reproduction: The skin is constructed of two layers, the epidermis and the dermis. Most mammals have three distinct kinds of hair: guard hairs, underfur, and whiskers.