Mexico is a biodiverse country. The dynamics of environments from Mexico played a crucial role in the history of North American biota. This book analyzes the paleoenvironmental conditions using several biological groups and various methods. This book also demonstrates how this information is specifically used to elucidate Mexico‘s past environments and habitats (terrestrial, freshwater, and marine). This book fills an existing editorial gap since much of the information is dispersed in several bibliographic sources. The authors are active paleontologists in diverse Mexican universities and research centers. Their research activities contribute to the knowledge of the Mexican biota through geologic time.