Prime objective of this lecture is to present on Animal Science. Here briefly describe on Triassic and Jurassic periods 180-135 million years ago. 1st there were only dinosaurs, mammal-like reptiles, and sea creatures. When dinosaurs were most abundant, the first birds and very small mammals were seen. Finally focus on What is the definition of Animal Science; what was the first life on earth; what is a vertebrate; and how did mammals survive when dinosor didn’t?