<span>The dinosaurs and the mammals appeared during the Triassic period, roughly 225 million years ago. The dinosaurs went extinct 65 million years ago. The Mesozoic Era lasted about 180 million years, and is divided into three periods, the Triassic, the Jurassic, and the Cretaceous.</span>
It’s red shift and blue shift, because this only occurs when the frequency of the wave is made longer or shorter due to the movement of the source relative to the observer.
