Question

Which one is a match?
(i) Cenozoic: 2 - 65 mya: Origin of vertebrates
(ii) Palaeozoic: 500 - 165 mya: Rise of egg-laying mammals
(iii) Mesozoic: 135 - 225 mya: Reptiles dominant
(iv) Proterozoic: 350 - 600 mya: Trilobites dominant.

• A. i
• B. ii
• C. iii
• D. iv

Answer 1

The correct option is A i

• The earth contains different layers of sediments, of which the bottom layer is the oldest layer and the upper layer is the most recent layer. Based on the age of rocks, a time scale was prepared and it is called the geological time scale, it depicts the different stages of the evolution of life on the earth over the past millions of years.
• It consists of three Eons, that consists of Eras which are divided into Periods that may be further subdivided into Epochs. These Eras, Periods, Epochs depict the time of origin and the dominance of the certain group of animals during certain Eras or Periods. It provides the most direct evidence for the concept of evolution.
  
• In order from oldest to youngest, the three Eons are as follows

Archean Eon: ancient or archaic (oldest rocks on earth)

Proterozoic Eon: beginning life (2.5 billion to 542 million years ago)

Phanerozoic Eon: visible life (542 million years ago to present).

• There are eras in the Phanerozoic eon. In order from oldest to youngest, they are as follows:
• 1)Precambrian Era: earliest part of earth's history.
  

2)Paleozoic Era: ancient life (such as trilobites)

3)Mesozoic Era: middle life (such as dinosaurs)

4)Cenozoic Era: recent life (such as mammals and flowering plants).
So, the correct option is 'i'.