The first vertebrate to evolve is the bony fish. Before that there were jawless fish. The amphibians evolved next after fish. It is the first vertebrate to live both on land and in water. They have few characteristics of fish in their early life. The reptiles evolved from the amphibians. They live entirely on land. From the amphibians, there developed certain added features such as feather, hollow bones and warm blood. These animals were called as birds or aves.