Description There are over 300 different species of turtles. They live in deep ocean waters to dry dessert habitats and range in size from small box turtles to gigantic Galapagos tortoises. They all have shells as part of their skeleton but some shells are flat andothers are large domes. Some turtles can pull heads into shells for protection but others cannot. Some are herbivores and others are omnivores but none have teeth. Learn more about what these reptiles have in common and how they are different through thelatest edition of the Compare and Contrast Book series.