But some land turtles can move with surprising speed. For example, the smooth softshell turtle, a freshwater species of North America, often can outrun a human being on level ground. The first turtles lived more than 185 million years ago. This creature died out, as did many other species. Today, many species of turtles face extinction because people hunt them for food and for their shells and gather their eggs.
People also destroy their natural homes to make way for cities and farms.
At one time, pet shops throughout the United States sold thousands of painted turtles and red-eared turtles yearly. But medical researchers discovered that many of these turtles carried bacteria that cause salmonella poisoning, a serious illness in human beings. In 1975, the U.S. Food and Drug Administration banned the sale of most pet turtles. The Body of a Turtle Shell. Most species of turtles can pull their head, legs, and tail into their shell for protection.