Age of mammals and birds is

Which era could be called the "age of mammals and birds " ?

Which of the following is commonly called ''age of mammals and birds''

Age of Mammals is

Age of Mammals is

Uricotelism is found in (a) birds, reptiles and insects (b) frogs and toads (c) mammals and birds (d) fishes and fresh water protozoans

Which epoch is called "age of mammals and angiosperms"?

Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?

Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds.

The character which differentiates mammals from birds is