The zygomatic process in mammals arises from

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 are exclusively viviparous?

$A$ mammal which lays eggs instead of giving birth to offspring is

Which class of animals secretes fresh milk for the nourishment of their young ones?

Egg-laying mammals are found in: