Säugetiers

Säugetiere, also Mammalia, represent a class of vertebrate animals characterized by several distinct traits. A primary defining feature is the presence of mammary glands, which produce milk to nourish their young. This lactation is unique to mammals and is crucial for the survival and development of their offspring. Another hallmark is the presence of hair or fur, which serves to insulate the body and maintain a stable internal temperature. Mammals are endothermic, meaning they generate their own body heat, allowing them to thrive in a wide range of environments, from frigid polar regions to scorching deserts.

Most mammals give birth to live young, a process known as viviparity, although a small group, the monotremes (like the platypus and echidna), lay eggs. Mammals possess a diaphragm, a muscular partition that aids in respiration, and a neocortex, a region of the brain associated with higher cognitive functions such as sensory perception, spatial reasoning, and conscious thought. Their circulatory system is characterized by a four-chambered heart, which efficiently separates oxygenated and deoxygenated blood. The diversity of mammals is immense, encompassing a vast array of forms, sizes, and lifestyles, from tiny shrews and bats to enormous whales and elephants, occupying nearly every ecological niche on Earth.