Question

Age of mammals and birds is
A. Mesozoic
B. Cenozoic
C. Archaeozoic
D. Paleozoic

Answer 1

Hint:- There are 3 geologic eras which are identified up to now, they are the Paleozoic, the
Mesozoic era, the Cenozoic era, where the names of all these eras reflect the relative stage in the
development of life, that are Paleozoic means old life and Mesozoic means middle life and Cenozoic means new life.

Complete answer:
1. When coming to the Paleozoic era, it is the oldest of all three eras, and this era was a range of
540 million to 248 million years ago.
2. During this Paleozoic era, a multi celled living organism acquired hard body parts such as bones,
vertebral column, and mouthparts like mandible and teeth.
3. The animals that were occupied by the Paleozoic era were trilobites, fishes, insects, reptiles, and
amphibians.
4. After the Paleozoic era, the next era was started which was established 248millions to 65 million
years ago.
5. The Mesozoic era was important as this is the era where fossils of the dinosaurs remain, and
other reptiles also lived.
6. The land of the Mesozoic era was occupied by insects, early birds, early mammals, and when
coming to plants, it is the era where first vascular plants such as ferns are seen, and this era also
has flowering plants.
7. The Cenozoic era is the most recent of 3 eras, and this era is called the age of mammals, the age
of birds, and age of flowering plants.
8. The Cenozoic era was recent and began 65 million years ago. And this era was opened by early
mammals and early birds.
So the correct option is B.

Note:- As given above, even though early mammals and birds are started in the Mesozoic era, which was a middle age era, and in that there is a begin of mammals and birds, but they are not species, while the recent era that is Cenozoic was fully occupied by birds, mammals, hence the Cenozoic era is called as age of mammals and birds.