breed Library > Turtle > All Turtles and Tortoises
Description
Turtles are reptiles of the order Testudines, most of whose body is shielded by a special bony or cartilagenous shell developed from their ribs. The order of Testudines includes both extant (living) and extinct species, the earliest turtles being known from the early Triassic Period, making turtles one of the oldest reptile groups, and a much more ancient group than the lizards and snakes. About 300 species are alive today. Some species of turtles are highly endangered.
Things to Note
Turtles are thought to have exceptional night vision due to the unusually large amount of rod cells in their retinas. Normal daytime vision is marginal at best due to their color-blindness and poor visual acuity. In addition to daytime vision problems, turtles have very poor pursuit movement abilities, which is most likely due to the fact that pursuit movement abilities are normally reserved for predators that hunt quick moving prey.
Turtles use their jaws to cut and chew food. Instead of teeth, the upper and lower jaws of the turtle are covered by horny ridges. Carnivorous turtles usually have knife-sharp ridges for slicing through their prey. Herbivourous turtles have serrated edged ridges that help them cut through tough plants. Turtles use their tongues to swallow food, but they can't, unlike most reptiles, stick out their tongues to catch food.