A reptile is a creature that possesses the features of both land and water animals, such as lizards and snakes. These creatures typically have scales and are covered with tough outer shells that are either hard or leathery. There are more than 10,000 reptile species around the world and they thrive on every continent except Antarctica. Some of them are quite large, such as the saltwater crocodiles that can grow up to 20 feet long and weigh up to 3000 pounds. Others are tiny, such as the chameleons that can change their colors to match their surroundings.

1. Reptiles Are Older Than Birds and Mammals.

Reptiles are one of the oldest groups of animals and their ancestors appeared in the Carboniferous period some 350 million years ago. These early reptiles were called cotylosaurs and looked similar to modern-day lizards. Over time, these ancestors evolved into the lizards, turtles, alligators and snakes we see today.

2. All Reptiles Have Scales.

The skin of reptiles provides protection from predators and the sun, while also allowing them to maintain an ideal body temperature. These scales are made of a tough material called keratin, which is the same chemical that makes up our hair and fingernails. The scales of a lizard or snake can be shed as they grow, and the process happens more often when the animal is younger.

3. Many Reptiles Can Smell With Their Tongues.

Snakes and lizards do not have noses, instead they smell using a sensory organ in their mouths called the Jacobson’s organ. When they flick their tongues into the air, they collect small chemical scent particles and transfer them to this organ via two grooves on the roof of their mouths. This information is then sent to the brain, enabling the reptile to detect odors.

4. Many Reptiles Show Temperature-Dependent Sex Determination.

Many reptiles, such as lizards and tortoises, can determine their own sex by the ambient temperature they are exposed to when they are developing inside an egg. The sex of some turtles is determined by the temperature at the moment of hatching, and this can help protect them from diseases that can affect their offspring. Gbosky

5. Most Reptiles Lay Eggs.

Many lizards and snakes are oviparous, meaning they lay hard-shelled eggs that develop and hatch internally. This allows the embryos to be protected and gives them a better chance at survival. However, a number of lizards, such as rattlesnakes and garter snakes, are ovoviviparous and give birth to live young. These lizards are born into their environment and must quickly learn to survive on their own.

6. Some Reptiles Can Shed Their Skin At Different Times Of The Year.

Depending on the species, some reptiles may need to shed their skin up to twice a year. The exact reason for this is not fully understood but it may be related to their growth rate. Some shedding is also done to keep the skin healthy and prevent it from drying out or becoming infested with mites.