Differences between reptiles and amphibians - Physical, reproductive and feeding

2024 Author: Carl Johnson | [email protected]. Last modified: 2023-12-16 06:19

Vertebrates include, among others, reptiles and amphibians, which, in turn, are part of the tetrapods, a term that refers to the presence of four extremities used to move or manipulate. Reptiles were the first truly terrestrial vertebrates, while amphibians are a group with transitional traits between fish and reptiles. Although some have managed to conquer the terrestrial environment, most depend on water, so they must stay close to it.

In this article on our site we want to introduce you to the differences between reptiles and amphibians. We invite you to continue reading so you can learn about the main features that characterize each of these groups.

Classification of reptiles and amphibians

In general, the classification of animals is not an absolute and invariable fact, but rather, thanks to scientific advances, discoveries are made that allow establishing changes in the taxonomic location of the groups and of the species. Below we present, in a general way, the traditional Linnaean classification and the cladistic or more current classification of living groups.

Reptiles

This is how reptiles are classified according to the Linnaean classification:

Order Testudines (turtles).
Order Squamous (snakes, blind shingles, and lizards).
Order Sphenodontos (tuatara).
Order Crocodilios (crocodiles).

Now the cladistic classification establishes an organization based on evolutionary relationships and does not use the term reptiles to refer to the aforementioned animals. One of the ways in which this science groups them is as follows:

Lepidosaurs: Sphenodon (tuataras) and Squamata (lizards, blind snakes and snakes).
Arcosaurs: crocodiles and birds.
Testudines: turtles.

Amphibians

Regarding the classification of amphibians, there are not so many divergences, so there are general agreements on their taxonomy and, depending on whether the Linnaean or cladistic classification is followed, the terms order or clade, respectively. Thus, we have that amphibians are classified in:

Gymnofiones: caecilians.
Caudata (urodeles): salamanders and newts.
Anura (salientia): frogs and toads.

Differences between reptiles and amphibians - Classification of reptiles and amphibians

Physical characteristics of reptiles and amphibians

Next, let's learn about the main characteristics of both groups.

Physical traits of reptiles

These are the most remarkable physical aspects of this group of animals:

The body is variable, in some it is compact and in others it is elongated.
They are Covered with horny scales, in certain groups there are epidermal bony plates and very few glands.
Limbs generally have five fingers and are adapted for running, climbing or swimming. But in some there are no limbs.
Well defined and developed bone formation. They have a sternum, with exceptions, and a rib cage.
They present chromatophores that allow them to exhibit a variety of colors.
The jaw is well developed and has teeth capable of generating a great force of pressure.

Physical traits of amphibians

This is basically the physical characteristics of amphibians:

Mainly bony skeleton, variable vertebrae and in some there are ribs.
The shape of the body is variable. Some have well-differentiated heads, necks, trunks, and limbs. Others are rather compact, with a fused head and trunk and no neck definition.
A few lack limbs, they are legless. Others have four distinct limbs, although in some cases the front ones are smaller than the back ones. There are also those with two pairs of small limbs and without functionality.
Usually feet are webbed and without true nails. Depending on the group they may have five, four or fewer fingers.
They have chromatophores that offer them a variety of colors, as well as various glands that in some cases are poisonous.
The skin is smooth, moist and practically free of scales, except for some cases where they are embedded in the skin.
They have mouths, usually large and with teeth on both jaws or sometimes just the top.

Differences between reptiles and amphibians - Physical characteristics of reptiles and amphibians

Reproduction of reptiles and amphibians

Within the differences between amphibians and reptiles we find those referring to the reproductive process:

Reproduction of reptiles

Reptiles that have separate sexes have some organ for internal fertilization Males have paired testicles that produce sperm, which is carried by the vas deferens to the evagination present in the wall of the cloaca, which constitutes the copulatory organ.

For their part, the females have a pair of ovaries, with oviducts that are responsible for producing nutritional substances for the embryo and the protective shell. These animals evolved to lay their eggs on land, as they are made up of a shell and internal membranes, which together provide protection and nutrition, allowing laying to take place in spaces dry

Newborns are born as lungworms and not as larvae that require water. There are some cases of reptiles viviparous in which certain transformations have occurred to generate a kind of placenta.

Reproduction of amphibians

Amphibians have separate sexes and internal or external fertilization In the group of salamanders and caecilians, fertilization is generally internal, while in toads and frogs it is usually external. In these animals the oviparous form of reproduction predominates, however, there are ovoviviparous and viviparous cases.

Also, a fairly general trait in almost all groups is the development of metamorphosis, so there is a transformation, well marked, between the larval and adult forms. Although there are certain exceptions in this regard, as occurs in the case of certain species of axolotls in which the larval features are maintained in the adult form, which is known as neoteny Also in certain terrestrial species of salamanders there is direct development, that is, at birth they have an appearance very similar to that of an adult.

For the most part, amphibians, if they do not require a body of water to lay their eggs, need humid places to lay, so they use leaves with accumulated water, they dig in the ground where appropriate temperatures are maintained and humidity is protected and even certain frogs lay their eggs on the ground and bring them water to keep them hydrated.

Feeding of reptiles and amphibians

In principle, it is important to mention that both reptiles and amphibians have a marked difference in feeding. The former have developed a much higher bite force than the latter. Also, reptiles have stronger teeth than amphibians. On the other hand, although with certain differences, there are species of both groups that have fleshy and extensible tongues that allow them to catch their prey.

As for the type of feeding, there are species of herbivorous and carnivorous reptiles Iguanas belong to the first group, while crocodiles are carnivores. For their part, amphibians are mostly carnivorous, although, generally, the larval forms consume plant matter.

Habitat of reptiles and amphibians

Reptiles are animals with a wide global distribution Many they develop in terrestrial habitats, but there are cases with arboreal customs and even some that, although they breathe on the surface, frequently remain in the water.

The amphibians are a very widespread group on the planet and, in terms of habitat, it should be noted that, being a intermediate group between fish and reptiles, they require, in most cases, aquatic habitats or, at least, with good humiditySome amphibians spend their entire lives in the water and there are also those that transit between both environments. Others, even near water, remain buried underground.

How to differentiate between amphibians and reptiles?

These are the details we can look at to easily differentiate amphibians from reptiles:

For your skin. In amphibians there are no scales and a soft and moist skin is observed. In reptiles, the scales are easily evident, which offers a dry appearance and a harder and thicker cover.
For their eggs. Amphibians place them in gelatinous masses, since they do not form a hard protection for themselves. Reptiles, when they are oviparous, lay eggs with shells.
For his metamorphosis. Most amphibians undergo metamorphosis, while reptiles do not.

Examples of reptiles and amphibians

Both reptiles and amphibians are two very diverse groups that, between them, add up to thousands of species. Here are some examples of reptiles and amphibians.