Introduction
The following article discusses the subtle differences between reptiles and amphibians. In general, they are grouped in biological classifications because their cold-blooded structure gives them common characteristics and evolutionary history. However, crocodiles and alligators are not included in this article because they are considered by many to be more closely related to birds than amphibians or reptiles. Students should keep in mind that all reptiles and amphibians also share some common features such as dry skin (instead of hair), scales (or feathers), lungs (instead of a diaphragm), and laying eggs (excluding live birth).
What are Reptiles?
The term reptile originated from Latin "repere". It meant "to crawl", which is a defining aspect of reptiles. Those are members of Class Reptilia which are cold-blooded animals. Moreover, it has four orders –
Crocodilia
Example – Crocodile, alligator
Squamata
Example – lizard, snake
Testudines
Example – Turtle, tortoise
Sphenodontia
Example – Tuataras
Characteristics of Reptiles
The main characteristics are –
Prefers to live in warm habitats
Presence of nasal slits and Jacobson's organ (except in crocodile and turtle)
Body covered by scales
Note that the main difference between mammals and reptiles can be seen in body covering. The presence of body hair is a defining characteristic of mammals, whereas reptiles have a keratin epidermal layer called scales. Consequently, mammals have sweat glands that are not present in reptiles.
What are Amphibians?
Amphibians are members of Class Amphibia, which live both on land and water. Furthermore, it primarily comprises three orders –
Anura
Example – Frog
Urodela
Example – Salamander
Apoda
Example – Caecilians
Characteristics of Amphibians
The main characteristics are –
Amphibians cannot regulate body temperature
Existence of larval stage that starts after eggs are hatched
They can live both inland and in water. Hence, amphibians can breathe both through gills and lungs.
Fun Facts!
While reproduction of any living being is a natural course, in the case of reptiles, it is dependent on temperature to a large extent. In addition, most of the reptiles lay eggs except pythons and boas, which give birth to young ones.
Moreover, it is the soil temperature that determines whether the new hatchling will be male or female!
Difference Between Amphibians and Reptiles
It is considered that reptiles primarily originated from amphibians, environmental factors led to the evolution of the former species. Thereby, the unique features apparent in amphibians and reptiles' differences helped to ensure the survival of these species.
Similarities Between Amphibians and Reptiles
Even though there are differences between amphibians and reptiles in points, owing to amphibians previously zoologically classified as reptiles leads to similarities shared by the species. Both belong to the phylum Chordata and subphylum Vertebrata.
Body metabolism is ectothermic. That is, body temperature changes corresponding to extraneous factors
Omnivorous eating habit
Presence of the cloaca as the common outlet for intestinal, urinary and genital functions
Reflex spinal segments help in locomotion
Test Your Knowledge
i. Reptile Eggs are Also -
(a) Waterless
(b) Amniotic
(c) Prehistoric
(d) Gigantor
ii. Tail-Less Amphibian Found Under Which Order?
(a) Order Anura
(b) Order Caudata
(c) Order Gymnophiona
(d) Both under order Gymnophiona and order Caudata
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Conclusion
Reptiles and amphibians are two different types of animals belonging to the kingdom Animalia. The main difference between amphibians and reptiles can be seen in their physiological adaptations, body covering, mode of reproduction, egg structure and presence/absence of limbs. Reptiles are cold-blooded animals whose skin is covered by scales, whereas amphibians are those whose skin lacks scales and is poisonous. Amphibians metamorphosis as they grow, whereas reptiles do not undergo such a process. Reptiles lay eggs, whereas amphibians give birth to live young ones. Furthermore, it is the soil temperature that determines whether baby reptiles will be male or female!
Hope you all liked this article on the difference between amphibians and reptiles. Keep learning, and stay tuned to Vedantu!
FAQs on Difference Between Reptiles and Amphibians
1. Why do reptiles and amphibians have cloaca?
Reptiles and amphibians have cloaca for excretion. It is helpful in containing the digestive, urinary and reproductive components under one common cavity. The reptiles and amphibians difference is mainly seen in limbs - limbs developed or not developed. More pointedly, some do not possess either front (anterior) or back (posterior) limbs. Amphibians, on the other hand, have front and back limbs. It is a fact that amphibians evolved from reptiles, but the major difference in their structure can be seen in front and back limbs. Amphibian species are diverse concerning their limb characteristics, but they all have front and back limbs. Reptiles are more evolved than amphibians concerning the structure of their limbs. On the other hand, most Amphibians have four legs, but the structure of their limbs is diverse. Some have front legs only, while some have both front and back legs. They are important in the movement of Amphibians.
2. What is the major difference between Amphibia and Reptilia classifications?
The Amphibia and Reptilia classifications are entirely different from one another, the only similarity being the presence of reptiles in both classes. The difference can be seen in several aspects- Amphibia include frogs, salamanders, caecilians while Reptilia includes Lizards, Snakes, Crocodiles, Turtles Terrapins etc., The frog species is called an amphibian while the turtles are reptiles. Some of the salamander species are considered amphibians, but most of them are reptiles. The major difference between Amphibia and Reptilia is that amphibians are ectothermic (cold-blooded) while reptiles are endothermic (warm-blooded). Students should keep this difference in mind while studying the different classifications under these groups. Our experts at Vedantu are well versed in assisting students with Biology homework help.
3. What can be inferred from the point that reptiles evolved from amphibians?
The inference is that amphibians are the ancestors of reptiles. Amphibians evolved from amphibian species which were living during prehistoric times. The presence of certain unique features in amphibians helps to distinguish them from other classes. Amphibians have different body shapes. While some are slender, others are stout-bodied. They also differ in size, the structure of the skull and limb characteristics. They live in freshwater habitats, while some live on land. When they feel threatened or sense danger, they can crawl out of the water quite effortlessly with the help of their pectoral limbs. One should not forget that amphibians are cold-blooded, while reptiles are warm-blooded. This fact plays an important role in differentiating the two.
4. What are the major ways of reptiles reproduction?
Reptiles reproduce sexually by internal fertilization. This is unlike amphibians that rely on external fertilization for reproduction. In reptiles, the male excretes sperms inside the female's cloaca, while in the case of amphibians, the sperm passes through the skin into the female's body cavity. Arrangement of cloacas is also another difference. Male reptiles have two-headed penes, while the same is not present in the case of amphibians. A female reptile lays eggs that she covers with sand or soil. The female lays eggs in the nesting sites. An important point to remember is that reptile eggs are shelled while amphibian eggs are not shelled. Reptile eggs are round in shape, while amphibian eggs are oval. It is possible to distinguish the eggs of these two by simply looking at them. Amphibians hatch inside the bodies of the mother and continue to develop there. As a result, the egg size is small.
5. How do reptiles hatch from eggs?
The development of reptiles inside eggs is similar to that of amphibians. Reptiles consist of embryos with gill slits, tail and tailbud during development. There are three types of reptile breeds- oviparous, ovoviviparous and viviparous breeders. Among these, the first one lays the eggs and leaves them to the mother. The eggs hatch by themselves as there is no parental influence involved in their development. Some reptiles lay eggs and go off. They bury the eggs, and organisms like ants, beetles, and other creatures help in hatching the eggs for them. Still, others guard their nests until they hatch, which can take days or weeks. Some reptiles provide parental care till their young ones grow old and strong enough to survive independently. Reptiles such as crocodiles, alligators, lizards and turtles guard their nests till the eggs hatch.
6. What are the major aspects to differentiate between amphibians and reptiles?
The major difference between amphibians and reptiles are – amphibians can breathe both through lungs and gills and exhibit external fertilisation, whereas reptiles can only breathe through lungs and reproduce through internal fertilisation.
7. Mention similarities between reptiles and amphibians.
Despite the difference between amphibians and reptiles, those regulate their body temperature. Moreover, the cloaca is present and acts as a common passage for a genital, intestinal and urinary outlet.
8. What is the reason for reptiles and amphibians share similar characteristics?
The common physiological and anatomical features of reptiles and amphibians arise from the phylum and subphylum shared by them. Nevertheless, before the present taxonomy was put in place, reptiles and amphibians belong to the same group.
Solutions
i. (b) Amniotic
ii. (a) Order Anura
