Chapter 32.8, Problem 3C

Summary Introduction

To describe: The argument for classifying the birds and reptiles in a single clade.

Introduction: In the late Devonian era, the aquatic vertebrates are adapted to terrestrial vertebrates. This adaptation is an important step towards the evolution of modern terrestrial vertebrates. There are three major groups of amniotes. They are reptiles, aves, and mammalia. Initially, reptiles were not included in monophyletic group without aves. This is because reptiles include some aves but not all. By the late Carboniferous period, the amniotes had undergone adaptive radiation.