Mammals

= ﻿ Mammals are very diverse and they are the successful group of vertebrates. Mammals first appeared on Earth at about the same time as the dinosurs. During the reign of the dinosaurs, [Triassic-Cretaceous Periods] mammals were about the size of modern day cats. At the end of the Cretaceous Period, when the dinosaurs died out, mammals somehow survived. They slowly began to evolve into bigger,heavier vertebrates. During the Cenozoic Era, [Paleocene-Pleistocene Periods] mammals were very successful. Then, in the Pleistocene Period, a new kind of mammal took control of the world. This mammal was known as //homo sapiens.// =