Evolution — BIOLOGY STD 12 Science — Question

3. Cretaceous period of mesozoic era.

Explanation:

Cretaceous period of the mesozoic era was the last phase. It was considered as the longest phase of the mesozoic era. It was also known as the age of reptiles.

In this era, the mammals arose from the reptiles. The transition from reptile to mammal were the evolution of warm-bloodedness, of molar occlusion, of the three-ossicle middle ear, of hair, and of mammary glands.