From the archive record
Turtles are reptiles of the order Chelonii or Testudines characterised by a special bony or cartilaginous shell developed from their ribs and acting as a shield. The scientific term turtle embraces the species known in general usage as tortoises, sea turtles and terrapins as well as all turtles, which term is commonly used to refer only to swimming species. The order Chelonii or Testudines includes both extant (living) and extinct species. The earliest known turtles date from 220 million years ago, making turtles one of the oldest reptile groups and a more ancient group than lizards, snakes or crocodiles. Of the many species alive today, some are highly endangered. Like all other extant reptiles, turtles are ectotherms—their internal temperature varies according to the ambient environment,