what is mammals | How mammals evolved

What Is a Mammal?

  Mammals word derived from Latin mamma which means breast.

  Mammals are animals that have hair, are warm-blooded, and nourish their young with milk. Mammals have stronger jaw muscles and jaws.

  Mammals are vertebrate animals, constituting the class Mammalia are characterized by the presence of mammary glands which in females and sometimes males produce milk for feeding their young, fur or hair, and three middle ear bones. 

  These characteristics distinguish them from reptiles and birds, from which they diverged in the Late Triassic, 201–227 million years ago. 

  There are around 5,450 species of mammals.  Some modern-day mammals include people, apes, cats, dogs, mice, elephants, whales, and horses.