Changes

The upper shell of the turtle is called the [[carapace]], and the lower is called the [[plasmon]]; their structures varying among different turtles. Some of the aquatic turtle species, the [[soft-shelled turtles]], have their carapace covered with [[leather]]y skin.

The upper shell of the turtle is called the [[carapace]], and the lower is called the [[plasmon]]; their structures varying among different turtles. Some of the aquatic turtle species, the [[soft-shelled turtles]], have their carapace covered with [[leather]]y skin.

Turtles have no [[teeth]] but a horny sharp [[beak]] instead. They also lack a [[breastbone]], and their [[heart]] has three chambers like the heart of other reptiles, with the noted exception of [[crocodile]]s.

Turtles have no [[teeth]] but a horny sharp [[beak]] instead. The [[breastbone]] makes up the lower part of the shell, known as the plastron, while the ribs and vertebrae make up the upper shell, known as a carapace.  Their [[heart]] has three chambers like the heart of other reptiles, with the noted exception of [[crocodile]]s.

Anatomically, turtles and tortoises are divided into two basic groups:

Anatomically, turtles and tortoises are divided into two basic groups: