Turtles, tortoises and terrapins are the members of the order Chelonia. They are reptiles.
The largest turtle is the leatherback turtle which lives in the sea and can be up to 8 feet (2.4 meters) long (length of shell). The smallest is the bog turtle whose shell is only about four inches (ten centimeters) long. The heaviest is again the leatherback at 1,800 pounds (817 kilograms). The lightest is the speckled Cape tortoise at 5 ounces (142 grams). Some land tortoises can live over 150 years!
Representatives of one or more of these groups live all over the world on every continent except Antarctica. They live in most any habitat except for where it is extremely cold all the time. They can handle the desert but not the arctic. Sea turtles live in the ocean.
Most turtles will eat both animals and plants but some will only eat plants.
Large sharks prey on sea turtles and killer whales will eat leatherbacks. In North America, many animals eat turtles or their eggs: otters, frogs, crows, snakes, turtles, skunks, etc.
Turtles’ shells are attached to their spinal chords. Turtles live mostly in water and have webbed feet and flatter shells than tortoises which live mostly on land and don’t have webbed feet. Terrapins live in brackish water which is a mixture of fresh and salt water. They also have webbed feet and flatter shells. The fastest turtle is the leatherback. It can swim up to 22 mph (35 km/hr). The leatherback can also go the deepest. It can dive 3,000 feet (900 meters)! It has a special shell that is less rigid than other turtles’ shells and that allows it to handle the pressure at such extreme depths.