Tortoises, those unmistakable turtles, evolved from a lineage that split off from the familiar pond turtles roughly 100 million years ago. Over time, these plant-eating land turtles spread around the world, growing to an enormous size (depending on the species) and living so long that they have become the stuff of legends. By most accounts, they are indeed the longest-lived of the turtles, with good records suggesting individuals may live as long as 180 years (anecdotal records suggest that some reach ages of 200 years or more).Providing the first comprehensive treatment of North America's tortoises, "Biology and Conservation of North American Tortoises" brings together leading experts to give an overview of tortoise morphology, taxonomy, systematics, paleontology, physiology, ecology, behavior, reproduction, diet, growth, health, and conservation. The contributors carefully combine their own expertise and observations with results from studies conducted by hundreds of other researchers.