CONTENTS XXV 



CHAPTER VI 



Evolution of Body Form in the Fishes and Amphibians 



PAGE 



Earliest known fishes i6o 



Early armored fishes 165 



Primordial sharks 167 



Rise of modern fishes 169 



Evolution of the amphibians 177 



CHAPTER Vn 



Form Evolution of the Reptiles and Birds 



Earliest reptiles 184 



Mammal-like reptiles 191 



Adaptive radiation of reptiles 193 



Aquatic reptiles 198 



Carnivorous dinosaurs 210 



Herbivorous dinosaurs 216 



Flying reptiles 226 



Origin of birds 226 



Arrested reptilian evolution 231 



CHAPTER VHI 



Evolution of the IVIamm.als 



Origin of mammals 234 



Character evolution 27,8 



Causes of evolution 245 



Modes of evolution 251 



