External ears (pinnae) are found in:

Which of the following is a unique characteristic of mammals?

Assertion : The duck-billed Platypus and the spiny ant-eater,both are egg-laying animals yet they are grouped under mammals.
Reason : Both of them have seven cervical vertebrae and $12$ pairs of cranial nerves.

Which of the following is not viviparous?

Constant body temperature is found in

Which of the following is an oviparous mammal?