The Duration of the Earth’s History
The duration of the earth’s history has been divided into smaller spans called the eras. The five eras are Archeozoic era ‘Pre-Cambrian period’ Proterozoic era paleozoic era Mesozoic era ‘age of reptiles’ Cenozoic era ‘age of the mammals’ First mammal appeared 200 million ago in Triassic period. The Indian desert also known as Marusthali is …