The reptile’s body parts are the typical body parts of a land vertebrate species. They have a **well-developed skill, backbone, tail, and two lib girdles to which the four limbs are attached**. However, reptiles also have distinguishing characteristics that set them apart from other groups of animals like the amphibians, and these characteristics are dry, scaly skin, lungs, and eggs that are composed of various membranes.

The **reptile’s** body parts are the typical body parts of a land vertebrate species. They have a well-developed skill, backbone, tail, and two lib girdles to which the limbs are attached. However, reptiles also have distinguishing characteristics that set them apart from other groups of animals like the amphibians, and these characteristics are dry, scaly skin, lungs, and eggs that are composed of various membranes.

There are four identified groups of reptiles that are still living and surviving up to date and they are lizards and snakes, crocodilians, turtles and tortoises, and tuatara.

1. Lizards and snakes are under the **order Squamata**. These species are considered the “scaly reptiles”. Most of the species found in this order are able to camouflage for protection.

2. Crocodilians are under the **order Crocodilia**. This order includes all species of alligators, crocodiles, and caimans. These organisms are easily identified because of the presence of their long broad snout and squat semblance.

3. Turtles and tortoises belong to **order Testudines**. These species are characterized by having a shell that is built into their skeleton. The turtle’s backbone is created and formed at the center of its shell, specifically in the carapace (dorsal part of the shell).

4. Tuataras are the only living species of **order Sphenodonta**. These species have a similar appearance to the lizards, but unlike the lizards, they do not have external ears, they retain their primitive scales, and they have the presence of the so-called “third-eye” found at the top of the brain, where it functions to sense the sunlight intensity.

Terrestrial reptiles are unable to excrete ammonia directly. Instead, they convert ammonia into uric acid in the form of urine. First, the urine is reduced to crystals of uric acid while the excess water in the urine is absorbed by the cloaca. Then, the crystals form a pasty white solid. When compared to ammonia, the uric acid is less toxic and it needs only a little amount of water. Because of this, these reptiles are able to conserve the water inside their body.

Reptiles are considered **ectotherms**. These animals rely on behavior to aid them in regulating their body temperature. Most reptiles like turtles, lizards, and snakes bask in the sun during the day to keep themselves warm and to cool down they usually move to a shady place, burrow underground or stay in the water for a swim.

If the Earth would have a warmer temperature and a higher humidity, reptiles are able to survive since they have special adaptations for this kind of environment. As ectotherms, they are able to regulate their body temperature through different behaviors. In addition, their body covering and excretory system work efficiently to prevent water loss. Unlike amphibians, reptiles are able to reproduce without the need for water.