Question

____ era is the “age of birds and mammals”.
A. Mesozoic
B. Paleozoic
C. Cenozoic
D. Cretaceous

Answer 1

The word era refers to the span of time. An era can be defined as a span of time for the purpose of historiography or chronology. In simple words, it can be stated as a long distinct period of history.

Complete answer: The word era has been derived from the Latin word aera which means an epoch or an era from which time is reckoned. Initially, an era in English means the starting point of an age. The era is considered as the highest level in the chronology for the organization of the measurement of time. The various different subdivisions of eras according to the chronology are a geological era, cosmological era, calendar era, regnal era, and historiography. A subdivision of geologic time that divides an eon into smaller units of time is called the geologic era. The current geologic eon in the geologic time scale is the phanerozoic eon. The phanerozoic era is further divided into three eras called the paleozoic era, the mesozoic era, and the cenozoic era. Among the three eras of the phanerozoic era, The Cenozoic era is the most recent of animal history. The span of the Cenozoic era is only about 65 million years, after the end of the cretaceous period. The Cenozoic era is sometimes referred to as the “age of birds and mammals”.
So, option C is the correct option.

Note: The Cenozoic era is also called the age of mammals because mammals were the terrestrial animals that dominated the hemisphere. A great diversity of birds and animals dominated the earth during the Cenozoic era due to the extinction of many other species of life.