Mammalia - The Mammals | Wildlife Journal Junior All mammals share three characteristics not seen in other animals They have three middle ear bones, they have hair, and they produce milk for their young There are about 5,000 species of mammals Scientists have organized mammals into about 26 orders based on characteristics and structure There are three subclasses of mammals:
Animal Classification: Zoology Facts Importance - Free . . . This system classifies animals into various levels, such as kingdom (Animalia), class (Mammalia), order, family, genus, and species For example, a dog belongs to the kingdom Animalia, class Mammalia, order Carnivora, family Canidae, genus Canis, and species lupus
Mammals - Basic Biology Mammal animals evolved on land and are mostly four-legged animals but a number of species have moved back to the sea or evolved to life in the air and in trees Mammals are a class of animals that includes a wide range of different species Most species fall into a group known as placentals
What are mammals? A look at the characteristics . . . There are over 4,000 species of mammals, and this number is constantly changing as new species are discovered and others become extinct The average number of mammal species found in each order is 10-12, but there is significant variation among orders