däggdjursklassen

Däggdjursklassen, scientific name Mammalia, is a class of vertebrate animals that are distinguished by the presence of mammary glands, which in females produce milk for feeding their young. Other defining characteristics include a neocortex, the region of the brain involved in higher-order brain functions, as well as hair or fur, and three middle ear bones. Mammals are warm-blooded, meaning they regulate their own body temperature internally.

This diverse class encompasses a vast array of species found in nearly every habitat on Earth, from the deepest oceans to the highest mountains. Their evolutionary history is extensive, with fossil evidence suggesting their origins trace back to the Triassic period. Mammals reproduce sexually, with internal fertilization being the norm. The vast majority give birth to live young, though a small group, the monotremes, lay eggs.

The evolutionary success of mammals is attributed to a combination of adaptations, including their advanced sensory systems, efficient respiratory and circulatory systems, and complex social behaviors in many species. They play crucial roles in ecosystems worldwide, acting as predators, prey, herbivores, and seed dispersers, influencing biodiversity and ecological processes.