REPTILES

Reptiles are creatures that usually have either scaly skin or outer layers. These creatures are either four-legged or come from the family (descendants of) other creatures with four legs or are better-called tetrapods. There is often debate about what creatures are amphibians and what are reptiles. I will be addressing the differences between the two later on in the article. However, let’s focus on reptiles and their characteristics. The reason reptiles have scaly, bony, or rough skin is that they have adapted to living on land over centuries and to reduce the amount of water lost from their skin’s surface.

 WHAT ARE REPTILES’ CHARACTERISTICS?

As previously mentioned, several characteristics precisely define what reptiles are. However, we can not take a single element and deem any animal or creature that fits the criteria as a reptile. For instance, reptiles are tetrapods, but we cannot declare dogs as reptiles. Together, these characteristics are vital for deciding if or not a creature is a reptile. Some of the key features are

 REPTILES ARE VERTEBRATES

Reptiles are organisms with backbones. They have a strong skeletal structure and are often tetrapods. Tetrapods are creatures that are four-legged creatures. This feature may not be dominant in the creature itself but could be ancestral. A Snake, for example, is limbless but is still a reptile because they come from a species that has four legs and still have the remains of limbs attached to their pelvis. 

REPTILES ARE COLD-BLOODED

The reptiles are not endothermic but ectothermic. This means that they are cold-blooded. Another fascinating feature is that these reptiles’ body temperature adjusts to the surrounding conditions. They lack the ability to sweat and shiver. If they want heat, they have to approach the sun, and if it is too hot, they have to resort to hibernation or going underground.

REPTILES HAVE SCALY SKIN

This is a major identifying factor as to whether a creature is a reptile. Now there is a reason why these reptiles have a rough, scaly outer covering or skin. Over years of evolution, a number of reptiles migrated to live on the land. So this means that they are more prone to losing moisture than being underwater. To prevent water loss via surface evaporation, their skins or coverings got hardened by the same substance that constitutes the human nails and a substance called Keratin. Snakes, iguanas, and alligators are all reptiles.

REPTILES LAY EGGS

All reptiles reproduce by laying eggs or are oviparous. However, there are certain exceptions to this. The reptiles lay eggs, and the mother stays with the eggs and protects them until they hatch. Some reptiles are viviparous, meaning that the infants remain in the mother until they are ready to be born. An example of this is the green snake Anaconda.There is a third type to this: ovoviviparous, which means that the infants stay in the eggs, but the eggs remain inside of the mother.

TYPES OF REPTILES

All reptiles broadly fall under one of four classifications or types.

Crocodilia:  

• This classification includes alligators, crocodiles, and gharials. These are the closest to the bird family.
• They have been around for 170 million years yet have had a slight variation.
•  They stay in the water for most of the time and hence are semi-aquatic.
•  It consists of 25 species amongst three families.
• Display nesting and child-caring behavior, which is what brings them close to the bird family.

Rhynocephelia:

• This type has one main species called the Tuatara and two subspecies.
• Tuatara is only the continent of Australia and is similar to the lizard family (Squamata), but they split from that family nearly 210 million years ago.
• The reptiles in this category existed in abundance about 150 million years ago but have faced significant extinction, and today the Tuatara is the only survivor.

Squamata:

• Squamata, translated into Latin means “scaled,”  includes all the snakes and lizards and has the most significant number of species (over 10,000).
• It has been the most successful in surviving evolution and has spread to all continents apart from Antarctica.
• These reptiles have a movable quadrate bone in their Jaw, which helps hunt prey. The snakes can swallow large prey due to this.
• This classification has two subclasses; Serpentes mean snakes, and Sauria refers to lizards.

 Testudines:

• The reptiles that come under this classification are all shelled. These include turtles, tortoises, etc.
• These reptiles have their shells fused with the vertebrae and are tetrapods.
• These, unlike other reptiles like snakes and iguanas, are herbivores.

CONCLUSION

Reptiles have undergone years of evolution and are predators that have very distinct features. Yes, there are similarities between the two, like being cold-blooded, laying eggs, and relying on the surrounding weather to adjust their body conditions. Despite several similarities between amphibians and reptiles, the reptiles have several characteristics that set them apart. Reptiles, for instance, are equipped with lungs to breathe, while amphibians have gills. So, therefore, it cannot be said that they are the same.