Why the bat is not called a bird?

A bat bears the following Mammalian features and since it lacks the basic avian features, it is a mammal and not a bird:

1. Body covered with hairs instead of features.

2. Patagium is made of skin and not of feathers.

3. Presence of teeth, but not the beak.

4. Viviparous with mammae.

5. External Pinna present.

Related posts:

1. Features of the phylum Mammalia
2. General features of the phylum Amphibia
3. Features of the phylum Reptilia
4. General features of Pisces/ Fishes
5. Features of the phylum Mollusca

Tags: bat