- Morphological evidence suggests that turtles, having existed for more than 200 million years, are the oldest of all surviving reptiles. Mostly aquatic or semi-aquatic, and having a bony shell, turtles can range in size from four inches (10 centimeters) to over five feet (1.5 meters) long. The upper shell is called the carapace and the lower shell is the plastron. As for the difference between a turtle and a tortoise: in America, tortoise refers to a kind of terrestrial turtle, brown in color, with a high-domed shell which completely covers the reptile whose head and limbs are drawn inside. In Australia and Great Britain, the words turtle " and "tortoise" are practically interchangeable. Almost half of the known turtle species are rare, threatened, or endangered. To increase awareness of the plight of the disappearing reptiles, American Tortoise Rescue has named May 23 World Turtle Day.
"And the turtles, of course... All the turtles are free; As turtles and, maybe, all creatures should be." — Dr. Seuss, "Yertle the Turtle"