Snakes are reptiles.
A reptile (or reptile , according to another form accepted by the Royal Spanish Academy ) is a vertebrate animal that lacks legs or has very short legs , so that, when walking, it brushes the ground with its belly. These are animals that can be oviparous or ovoviviparous and have a variable temperature.
The skin of reptiles is covered with scales of keratin , a protein substance that is rich in sulfur. In this way, reptiles can live in very dry habitats, such as deserts.
These vertebrates have a pulmonary respiratory system and communicate in various ways, either through the emission of sounds, visually or through pheromones.
Evolution and classification of reptiles
Reptiles form one of the evolutionary branches of amniotes . They arose in the Carboniferous period from tetrapods , the clade of vertebrates with four limbs.
When it comes to classifying reptiles, two large groups are normally established, which are called anapsids and diapsids. We can state that the first of those mentioned is basically made up of turtles while the second is made up of two other differentiated groups: archosaurs and lepidosaurs.
Some reptiles have short legs, such as iguanas.
The archosaurs
Among the animals that fall within the archosaur typology we would have crocodiles. These are divided into fourteen species and their main identifying features are the fact that they have a lifespan that can reach 80 years, that they have a hard and scaly skin, that they feed on a wide variety of animals and that they choose as habitat tropical places such as, for example, those that exist in Africa or America.
Currently we find that crocodiles are subdivided into two large families: the mekosuchinae and the crocodylinae. The first of them has recently become extinct and was made up of species that could be found in both Australia and Oceania.
In the case of the second family, what must be highlighted is the fact that it is made up of reptiles such as caimans, alligators or gharials.
Lepidosaurs, other reptiles
Returning to the second group into which we divide the diapsids, the lepidosaurs, we have to state that it is made up of three clearly delimited species: the tuataras, which are similar to iguanas and are found in the New Zealand area; lizards and snakes.
Lizards or lacertilians make up the largest suborder of reptiles, including lizards , iguanas and chameleons , among other animals. It is estimated that, today, there are about 5,000 species of lizards.
Snakes or snakes are another suborder of reptiles, in this case characterized by the absence of limbs and elongated bodies. There are species of snake that have venomous bites.
Another suborder within reptiles is the turtles or chelonians , which have a shell that protects their internal organs. Turtles do not have teeth: their jaw is covered by a horny beak similar to that of birds.