Answer – Birds are not mammals. They are grouped under a class called Aves, while mammals are categorized under another class Mammalia. Both birds and mammals are, however, a part of the same subphylum Vertebrata of the animal classification system.

Explanation: 

All vertebrates (belonging to the subphylum Vertebrata) are classified into the following categories:

• Mammals under the class Mammalia
• Birds under the class Aves
• Reptiles under the class Reptilia 
• Amphibians under the class Amphibia 
• Fish under the below 3 classes:
  1. Osteichthyes (bony fish)
  2. Chondrichthyes (cartilaginous fish)
  3. Agnatha (jawless fish)

Birds and mammals are grouped into 2 separate classes because they have unique defining characteristics. All birds are identified by forelimbs modified into wings, a beak without teeth, a body covered by feathers, and the ability to lay eggs for reproduction. All mammals, on the other hand, possess a full set of teeth in the mouth, have fur or hair covering their bodies, give birth to offspring, and produce milk from mammary glands.

While they are starkly different from one another, birds and mammals (along with reptiles) are said to have descended from the same reptilian ancestor about 320 million years ago. Since then, however, the two groups have gradually evolved to possess the differentiating characteristics they have today.

Popular Questions