Classification of reptiles
The reptiles They are a group of vertebrate animals very old, which have been evolving and adapting to many environments on our planet for many thousands of years. Although they are often hated by many, reptiles have significant cultural significance as well as being important to the maintenance of populations of other animals, such as rodents, which can be a major source of disease for humans.
In this lesson from a TEACHER we will review the classification of reptiles, from the most primitive to the most complex, giving examples for each of them. If you want to know more about snakes, turtles, salamanders and more, keep reading!
Index
- What are reptiles? Basic characteristics of reptiles
- Sphenodonts or rhincocephals: living fossils
- The chelonians or turtles
- The crocodilids or crocodiles
- Ophidians or snakes
- Saurians or lizards
What are reptiles? Basic characteristics of reptiles.
The reptilesthey are animals vertebrates, who spend most of their time out of the water. Therefore, although they can swim and dive, they are generally classified as animals
terrestrial. Reptiles evolved from primitive amphibians and were the first vertebrates to spread on land. The most important adaptation that allowed them to conquer the land was the development of hard shell eggs, which protect them and make them not need water for their development.Other important characteristics of reptiles They are:
- Variable body temperature.
- Skin covered with scales, shields or horny plates and skin almost devoid of glands.
- Very ossified skeleton.
- Short or absent limbs.
- Pulmonary respiration and double and incomplete circulation.
- Tongue with gustatory, olfactory and tactile functions.
Taking into account bodily, behavioral, or physiological characteristics, zoologists have been able to make a Simple classification of reptiles into 5 groups: rhincocephalus, chelonians, crocodilids, snakes and saurians.
Image: 100cia.site
Sphenodonts or rhinocephals: living fossils.
Currently, the only living representatives of rhinocephalus they are the tuátaras or sphenedons, three species that live in some islands of New Zealand. The group of sphedones it is, therefore, what is called a living fossil.
This group is made up of species with very primitive characteristics, most of which lived more than 200 million years ago and disappeared. Among the most important characteristics of rhinocephalos is that they possess a pineal eye at the apex of the head.
This eye, although it looks like a normal eye covered by skin, is sensitive to sunlight and is involved in regulating the circadian rhythm and hormonal production for thermoregulation. They are mainly nocturnal and differs from lizards in that it has a bone arch on the skull, behind the eye.
The chelonians or turtles.
Turtles are a group of very primitive reptiles, which have remained intact for more than 200 million years. Their main characteristic is that they have a bony shell that covers almost the entire body. Short limbs emerge from the sides of the box-shaped shell.
One of the most unique characteristics of turtles is their jaws: arranged in the shape of a beak, without teeth and with sharp edges. These very sharp cutting edges allow them to feed on plants and / or small animals such as zooplankton, earthworms and even baby mice.
Within the turtles we can find: freshwater turtles, sea turtles, and true (terrestrial) turtles. All breathe through lungs, although some species of sea turtles are capable of diving for long distances.
Image: Zootecnia
Crocodilians or crocodiles.
Within the classification of reptiles we also have to talk about crocodiles. There is a total of 16 species of crocodiles, with representatives on all continents except Europe since they live exclusively in tropical areas, which are not found in Europe. Most of them live in Africa and the best known are: the Nile alligator, the Mississippi alligator, the black alligator, the spectacled alligator and the alligator.
Its body is elongated and, unlike other reptiles, they do not changes. Your skin has a very thick horny layer, which thickens throughout your life. They have the elongated snout and they own tapered and sharp teeth, located on the edge of the jaws, which they use to catch and kill their prey. At the extreme end of the body is the tail, its main swimming organ.
The crocodile's eye is protected by a transparent third eyelid (nictitating membrane) and its nostrils close during the dive. The marine crocodile is able to swim and remain motionless underwater for more than two hours.
Ophidians or snakes.
Snakes are reptiles with a cylindrical and elongated body, Without extremities, that move crawling with wave movements of his muscular body, formed by a large number of vertebrae. Unlike crocodiles, snakes do they moveperiodically your skin, so the scales that cover their skin are not as robust as those of crocodiles.
Snakes' mouths are very plastic and allow them to swallow their prey whole. The tongue is forked and mobile, which they use as a sensory organ for smell and touch. Some have hollow teeth, full of poison with which they can inject their prey.
There are about 2,700 species, classified into five groups. Non-poisonous families are: snakes and the boas or constrictors while poisonous are the cobras, vipers Y sea snakes.
Image: Zootecnia
Saurians or lizards.
We finish this classification of reptiles by talking about the lizards, animals that have skin covered with scales and small horny plaques. Their body is elongated and they have a long tail. They are distributed throughout the world, except in cold areas.
The most peculiar morphological characteristic is that they have large eyes, with mobile lids and five fingernails on each leg.
The different families of saurians are:
- gecko (geckos and geckos)
- iguanids (iguanas), chameleonids (chameleons)
- lacértids (lizards proper)
- varánids (like the Komodo dragon)
- splinters (skinks or skinks)
- agánidos (Old World iguanas, like the flying dragon or King's clamidosaurus).
Image: Zootecnia
If you want to read more articles similar to Classification of reptiles, we recommend that you enter our category of biology.
Bibliography
- Hickman C.P. Roberts L.S. Larson A. l’Anson H. & Eisenhour D.J. 2006. Comprehensive Principles of Zoology. 13th Ed. McGraw-Hill Interamericana. Madrid.
- Cobos, R. M., & Ribas, R. (1987). Reptiles: turtles, snakes, lizards. Small Animal Veterinary Clinic, 7 (3), 0133-150.
- Mendivil Navarro, J (s.f) Reptiles. Nature of Aragon. Recovered from: https://www.naturalezadearagon.com/fauna/reptiles.php
