Age of Earth

How can we classify the history of the Earth?

Like the history of human civilization, the history of the Earth too is divided into periods. However, these periods cover not just a few centuries, but millions of years. Broadly, we differentiate between the time preceding the period 550 million years ago and the time after that, during which life developed very quickly on the Earth. Researchers have gathered a lot of data regarding the different periods of the Earth's history by studying fossils. Thus, we came to know at what time fishes and birds appeared on the Earth, why plants and animals lived in the sea for so long, and what the different types of dinosaurs ate.

After the 'Archeozoic' period of the Precambian era, which lasted till about 550 million years ago, came the Paleozoic era. This era is subdivided into Cambrian, Ordovician, Silurian, Devonian, Carboniferous, and Permian periods. In the Cambrian period, different types of organism lived in the sea. The first land plants appeared in the Ordovician period. This fact can be proved with the help of fossils. The Mesozoic or the 'medieval age of the Earth', which is classified into the Triassic, Jurassic, and Cretaceous periods, began around 250 million years ago. The first mammals, as well as the dinosaurs, first appeared in the Triassic period. At the end of the Cretaceous period, the dinosaurs became extinct. Man evolved in the late Cenozoic, which started about 65 million years ago.

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