Information about reptiles
Reptiles include snakes, lizards, turtles, crocodiles, tuataras, and numerous extinct species. They are a group of vertebrates, animals that seem to come from the Mesozoic era when dinosaurs existed, but over time they had to adapt and underwent changes in their bodies, so many reptiles adapted to water and others to live on land, there are approximately 7,000 species. They are ectothermic animals, meaning their activity depends on environmental temperature; they usually seek warm areas.
Did you know? The king cobra can reach over 5 meters in length; it is the largest venomous snake in the world. It lays its eggs on land and not in water, as amphibians do. Snakes, like turtles, lizards, and crocodiles, are reptiles.
Characteristics
- They have dry and scaly skin, which prevents their tissues from drying out. In other cases, it also serves them for defense and mating. The scales of reptiles are mainly made of keratin and derive from the outer layer of the skin or epidermis, unlike the scales of fish, which are bony and dermal structures. The inner layer of the skin or dermis contains many blood vessels and nerves, as well as cells with pigmentation that give many species their bright colors.
- The color of most reptiles has shades of green, brown, and gray, allowing animals to better adapt to their environment. However, many turtles, lizards, and snakes display bright markings in blue, green, yellow, orange, or even purple. Some reptiles, especially chameleons and lizards, are capable of changing skin color by dispersing or concentrating pigment-bearing cells called chromatophores.
- Reptiles rely on their senses to feed and avoid predators. Species that hunt for food typically have eyes on the front of the head, allowing them to have binocular vision.
- Many reptiles are carnivorous, so they often have teeth that enable them to capture and kill their prey.
- There are also reptiles with dual respiration, such as aquatic turtles.
- They have a more advanced nervous system than amphibians.
- Like birds, most reptiles hatch from shell eggs that the mother deposits on the ground.
Did you know that reptiles bask in the Sun to warm up? They do this because they are cold-blooded animals.
Types of reptiles
Rhynchocephalians
They are similar to lizards, differing from them by osteological (anatomical) characteristics. Rhynchocephalians or Sphenodontids were abundant in the Triassic and Jurassic, but today they are all extinct, except for the tuatara of New Zealand.
Squamates
This group represented by lizards, snakes, and blind snakes, constitutes the largest group of living reptiles and includes 95% of all living species.
It is divided into three suborders: the suborder Lacertilia or Saurians (the lizards), the suborder Amphisbaenia (the blind snakes), and the suborder Serpentes (the snakes). Lizards first appear in the fossil record in the Permian, snakes in the late Cretaceous, and blind snakes in the early Cenozoic.
Testudines
This type of reptile has differentiated from other reptiles in the Triassic, and nowadays it includes sea turtles and land turtles. They are characterized by being covered with a shell consisting of a dorsal or back carapace and a ventral plastron. Species of this order are unique in that they have flat ribs on which the shell rests; since this bony shell makes the body walls rigid, the animals have to breathe using a process similar to swallowing (passage of food from the mouth to the pharynx and then to the esophagus).
Crocodiles
Crocodiles and alligators appeared in the late Triassic and are the closest living relatives of dinosaurs and birds. Their heart is almost completely divided into four chambers; the brain shows a higher degree of development, and they have an elongated and robust skull. Current species are included in 3 families: alligators and caimans, crocodiles, and gharials.
Ichthyosaurs
All members of this order, belonging to the subclass Diapsida, are extinct. Ichthyosaurs were large marine reptiles that had a body similar to that of dolphins and limb-like flippers, allowing them to reach lengths exceeding 4 meters.
Plesiosaurs
This order of extinct animals, included in the superorder within the subclass Diapsida, encompassed long-necked aquatic individuals with large bodies and limbs adapted to glide through the water.
Saurischians and Ornithischians
Dinosaurs, long-necked and tailed reptiles that first appear in Triassic strata, are included in the Saurischian and Ornithischian orders. They became common in later times until the end of the Mesozoic, when they became extinct.
Pterosaurs
Extinct flying reptiles equipped with membranous wings, similar to those of bats. The Pterosaur order is included in the superorder Archosauria, which also includes dinosaurs.
Therapsids
The Therapsid order, belonging to the subclass Synapsida, includes reptiles similar to mammals, which lived during the Permian and Triassic periods. Some were herbivores and others carnivores. It is believed that mammals descend from this lineage.
Feeding
Carnivores
There are some reptiles that are strict carnivores, meaning they only feed on the flesh of other animals. Most combine this type of feeding with others, but there are two large groups of reptiles that are exclusively carnivorous. These are snakes and crocodiles, and there are also aquatic carnivores such as sea turtles.
Insectivores
These reptiles base their diet on the ingestion of insects and small invertebrates such as spiders, mollusks, and worms. This group is known as insectivorous reptiles. Most of them have tongues with extremely fast movements to capture prey easily; a clear example of this type of reptile is lizards or chameleons.
Herbivores
We can also find reptiles that feed exclusively on plants and plant-based products. They are the least numerous, but they also have several species that make up this group. Examples of these reptiles are iguanas and lizards.
Omnivores
These types of reptiles have a different point of view than most species; they have a preference for one type of food or another, many of them combine different types of food and can adapt to one diet or another depending on the circumstances. That’s why most reptiles are said to be omnivores, although animal-origin nutrients predominate in their diet. In these cases, whether they feed on small vertebrates or invertebrates, they have a digestive system adapted to such situations.
Habitat
You can find reptiles in almost all places on Earth except Antarctica. Some live in oceans, like many sea turtles; in freshwater, like turtles and crocodiles, and there are also terrestrial reptiles, like lizards and geckos. They usually live in places where it is not too cold because, as you know, their bodies do not produce heat, and to warm up, they bask in the Sun.
Reproduction
They reproduce through internal fertilization. Males court or try to attract females. Some lizards change color to attract their attention. The male anole lizard inflates its neck to impress them. The male turtle shakes its head or touches the female’s face with its paws. Female snakes attract males by emitting a kind of perfume called pheromone.
Most reptiles are oviparous, meaning they lay eggs. Only a few species of lizards and snakes are ovoviviparous. In ovoviviparous animals, the egg develops inside the female’s body until the small reptile breaks the shell and is born.
Almost all reptiles can fend for themselves from birth. However, offspring, especially those of sea turtles, have very few chances of surviving during the first months of life. They are often eaten by birds, mammals, other reptiles, and even, in the case of sea turtles, by sharks. When they manage to get ahead, they can live for a long time.
Can you imagine the long life that some reptiles have? Like turtles that last more than 150 years, and caimans can live more than 70 years, while some small lizards only live between 4 and 5 years.
Help with the survival of these beautiful reptiles!
Humans are destroying the places where reptiles live. We also pollute the rivers, lakes, and swamps where these animals live. Additionally, they are hunted, and their eggs are collected for food. Some sea turtles are highly prized for making soup. Certain turtles and other reptiles are captured for sale as pets. Large lizards, snakes, and crocodiles are also hunted for their skins, which are used to make bags, belts, shoes, and wallets. This has led many species of reptiles to be endangered. Therefore, in many countries, there are laws that prohibit capturing certain species to prevent them from disappearing.