What are the differences between animals belonging to the Aves group and those in the mammalian group?

Q.:- What are the differences between animals belonging to the Aves group and those in the mammalian group?

 

Answer:-

Differences between in the mammalian group:-

S. No. Aves Mammalia
1. The body is covered with feathers. Their body is covered by skin with hair.
2. The forelimbs are modified for flight. The forelimbs are modified for climbing or for some other purposes.
3. Mammary glands are absent. Mammary glands are present. These produce milk to feed their young ones.
4. Bones are light and hollow. Bones are solid, hard and filled with bone marrow.
5. They lay eggs (oviparous). They produce young ones (viviparous). However, platypus and echidna lay eggs and some like Kangaroos give birth to very poorly developed young ones.