Facts about Turtles for Kids
Gathered by: B.Matthews
- Turtles are reptiles of the order Chelonii or Testudines characterised by a special bony or cartilaginous shell developed from their ribs that acts as a shield.
- The order Chelonii or Testudines includes both extant 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.
- Like all other extant reptiles, turtles are ectotherms — their internal temperature varies according to the ambient environment, commonly called cold-blooded.
- However, leatherback sea turtles have noticeably higher body temperature than surrounding water because of their high metabolic rate.
- Like other amniotes (reptiles, dinosaurs, birds, and mammals), they breathe air and do not lay eggs underwater, although many species live in or around water.
- Freshwater turtles are generally smaller, but with the largest species, the Asian softshell turtle Pelochelys cantorii, a few individuals have been reported up to 6.6 ft.
- Giant tortoises of the genera Geochelone, Meiolania, and others were relatively widely distributed around the world into prehistoric times, and are known to have existed in North and South America, Australia, and Africa.
- They became extinct at the same time as the appearance of man, and it is assumed humans hunted them for food.
- Turtles are divided into two groups, according to how they evolved a solution to the problem of withdrawing their necks into their shells: the Cryptodira, which can draw their necks in while contracting it under their spine; and the Pleurodira, which contract their necks to the side.
- Sea turtles possess glands near their eyes that produce salty tears that rid their body of excess salt taken in from the water they drink.
- The first proto-turtles are believed to have existed in the late Triassic Period of the Mesozoic era, about 220 million years ago, and their shell, which has remained a remarkably stable body plan, is thought to have evolved from bony extensions of their backbones and broad ribs that expanded and grew together to form a complete shell that offered protection at every stage of its evolution, even when the bony component of the shell was not complete.
- More recent morphological phylogenetic studies with this in mind placed turtles firmly within diapsids, slightly closer to Squamata than to Archosauria.