Life has been around since the dawn of earth, nearly 4.2 billion years ago, and all the lifeforms that we see around us today are the result of many aeons of evolution. From the very first single-celled organism to the first organism to crawl on to land, life has seen a multitude of species that have evolved, dominated and became extinct.
The dinosaurs were one such group of organisms that ruled the world roughly 65 million years ago. Mammals actually walked alongside dinosaurs, but they were rather small and were very vulnerable to predation. Learn more about evolution by exploring Class 12 Biology Revision Notes Chapter 7 – Evolution, right here on BYJU’s.