Difference Between Reptiles And Birds: (Reptiles Vs. Birds)
In this post, we will know about the key differences between Reptiles and Birds. After reading this post, you can perfectly differentiate the two of these very clearly.
Make sure to read this complete post to understand the topic very clearly and precisely.
Both Reptiles and Birds belong to Sub-phylum Vertebrata of Phylum Chordata of the Animal Kingdom.
Reptiles belong to Class Reptilia of the Animal Kingdom. Whereas, Birds belong to Class Aves of the Animal Kingdom.
Reptiles are all cold-blooded, terrestrial, or aquatic air-breathing animals. Whereas, Birds are all feather-clad, warm-blooded, air-breathing, bipedal animals.
Reptiles and birds are two important groups of animals. The morphology of these animals is very distinctive, but much of their physiology is similar.
Both reptiles and birds are economically and ecologically beneficial to humans and the environment.
And in evolution, it has been studied that reptiles are the phylogenetic ancestors of the birds. This means that reptiles arrived first and birds arrived with the implementation of various evolutionary changes in the reptiles.
Let’s know more about them with precise detail and comparison.
Comparison Chart: Reptiles Vs. Birds
| NO. | REPTILES | BIRDS |
|---|---|---|
| 1. | Reptiles belong to Class Reptilia. | Birds belong to Class Aves. |
| 2. | Reptiles have evolved from Amphibians. | Birds have evolved from Reptiles. |
| 3. | Reptiles have scales all over the body. | Birds have scales on their legs only and the rest of the skin is covered with feathers. |
| 4. | Reptiles are mostly carnivores. | Birds are herbivores, carnivores, and omnivores. |
| 5. | Reptiles being heavy weight and with a buoyant body, they can’t fly but swim. | Birds being lightweight and with the aerodynamic body, they can’t swim but fly. Though with some exception birds like duck, swans, etc. can swim but can’t fly. |
| 6. | Reptiles are cold-blooded. They cannot regulate their body temperature according to the environment. | Birds are warm-blooded. They can regulate their body temperature according to the environment. |
| 7. | They are both terrestrial and aquatic air-breathing animals. | They are terrestrial air-breathing animals. |
| 8. | Body is divided into: head, neck, trunk, and tail. Tail is long and scaly. | The body is divided into: head, neck, trunk, and tail. Tail is short and stumpy. |
| 9. | 2 pairs of limbs are present: Forelimbs and Hindlimbs. In snakes, limbs are totally absent. | 2 pairs of limbs are present: Forelimbs (modified to wings for flight), and Hindlimbs. |
| 10. | Forelimbs and Hindlimbs are with 5 digits and horny claws. | Forelimbs are with 3 clawless digits and feathers for flight. And, Hindlimbs are with 4 digits and claws. |
| 11. | They have powerful jaws with teeth. With some exceptions teeth are replaced by horny beaks in turtle and tortoises. | They have strong beaks with a curved tip or serrated ridges without any teeth. |
| 12. | Skin is dry, scaly, and the skin glands are absent. | Skin is dry, feathery, and with no skin glands. Only the oil glands are present at the base of the tail. |
| 13. | Bones are kinetic, free-moving, elastic, and very flexible with bone marrow. | Bones are kinetic, extremely free moving, elastic, and very flexible with hollow air cavities making it lightweight for flight. |
| 14. | Respiration takes place by the lungs throughout life. | Similar to reptiles, in birds too respiration takes place by lungs throughout life. |
| 15. | While breathing, air enters the lungs through the trachea, and then through the same trachea the air is breathed out. | In birds, air enters through the lungs, and after entering the lungs, it follows the lungs’ channels and leaves the lungs from the other side. |
| 16. | The heart is 3-chambered (2 auricles and 1 ventricle). In crocodiles the heart is 4-chamber (2 auricles and 2 ventricles). | The heart is 4-chambered (2 auricles and 2 ventricles). |
| 17. | Fertilization is internal and the fertilized eggs are laid outside. Only a few like boas and python give birth to young ones. | Fertilization is internal and the fertilized eggs are laid outside. |
| 18. | Reptiles tend to experience direct development. This means that the young ones are hatched looking like a miniature version of the adult parents. | Birds also tend to experience direct development. |
| 19. | Reptiles are uricotelic, ammonotelic, and ureotelic. They do have a bladder for excretion. | Birds are uricotelic as they have do not have any bladder. |
| 20. | Reptiles have pectoral girdle which consists of two similar halves. A sternum or pectoral girdle is absent in snakes. | Birds are the only vertebrate animals to have a fused collarbone (the furcula or wishbone) and a keeled breastbone. |
Definition of Reptiles
Reptiles are cold-blooded meaning that they are ectothermic that is they cannot regulate their body temperature according to the environment. They are hot when the temperature is hot and they are cold when the temperature is cold.
The origin of reptiles lies about 310–320 million years ago, in the steaming swamps of the late Carboniferous period. These were the first class of organisms to adapt to life on land after being evolved from the Amphibians.
Reptiles comprise present-day turtles, crocodiles, alligators, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives.
They are both terrestrial and aquatic air-breathing animals. That is they can stay both in water and land.
Their body is divided into head, trunk, neck, and tail. Their body surface is covered with horny scales or scutes.
These air-breathing vertebrates have a body surface that is covered in special skin made up of scales, bony plates, or a combination of both.
They have two pairs of limbs with 5 digits in each limb. In some reptiles, like snakes, the limbs are absent and they move using their flexible body muscles.
Reptiles are well-known to shed the outer layer of their skin. They are all egg-laying and only a few like boas and python give birth to young ones.
Reptiles do have a lighter skull that is modified that gives the reptiles an efficient and powerful kinetic jaw action.
Definition of Birds (Aves)
Birds are those animals with backbones that have wings and feathers.
Most birds can fly, using powerful muscles to flap their wings. But a few bird species do not have strong enough wings to fly, and so these birds are flightless.
Birds are warm-blooded meaning that they are endothermic that is they can regulate their body temperature according to the environment.
They can keep the inside of their bodies at a constant temperature by generating their own heat when they are in a cooler environment, and by cooling themselves when they are in a hotter environment.
The origin of the birds lies about 160 million years ago in China. They are descendants of the primitive avialans (whose members include Archaeopteryx).
These were the first class of organisms to adapt the life on both land and air after being evolved from the Reptiles.
The body of birds is roughly aerodynamic in nature. The body is boat-shaped and is divisible into head, neck, trunk, and tail. The tail is short and stumpy.
They have two pairs of limbs. The forelimbs are modified into feathers for flight. The hind limbs are composed of four digits adapted for walking, running, scratching, perching, swimming, or wading.
Their skeleton is light, spongy, and hollow containing air cavities that help them in flight. Their skull is light and is composed of beaks with no teeth.
Body epidermis is covered by feathers. Legs are covered by scales. You will find claws on the toes and sheath on beaks.
Key Differences Between Reptiles and Birds
1. Reptiles belong to Class Reptilia of the Animal Kingdom. Whereas, Birds belong to Class Aves of the Animal Kingdom.
2. Reptiles are cold-blooded. Whereas, Birds are warm-blooded.
3. Reptiles can stay both in land and water and are air-breathing using lungs. Whereas, birds can stay only in land and are also air-breathing using lungs.
4. Reptiles can swim, walk, and crawl. Whereas, birds can fly, and walk.
5. Reptiles could be lightweight as well as heavyweight. Whereas birds are usually lightweight animals but sometimes there are heavy ratite bird species with some exceptions as well.
6. Reptiles have scales all over the body, whereas birds have scales on the legs and the rest of the skin is covered with fluffy feathers.
7. Reptiles have a very slow metabolic rate. On the other hand, birds have a very fast metabolic rate.
8. As a result of metabolism, birds can produce their own body heat while reptiles due to their low metabolism rate cannot produce their own body heat.
9. Reptiles consume a very small amount of energy in nature whereas, birds are the highest energy-consuming animals.
10. When reptiles become ill, they lower their body temperature. On the other hand, when birds become ill, they increase their body temperature. Lowering body temperature help the reptiles to get rid of bacterial infections.
11. Reptiles have connected heart chambers that allow for the mixing of oxygenated and deoxygenated blood. Whereas, Birds have completely separate heart chambers for both the oxygenated blood and deoxygenated blood.
12. After birth, reptiles leave their young ones and the baby reptiles start to lead their life all by themselves. Whereas, birds do take care of their young until the young ones reach a stage when they can take care of themselves.
13. Reptiles lay large eggs that are covered with leathery shells that often adhere to one another. In the other case, birds lay leathery eggs where the shell usually hardens (calcifies) within a period of about 24 hours or so.
Conclusion
Both reptiles and birds are higher vertebrates. They both are distinctively different creatures that have evolved differently.
With being very different they are very similar as well with the presence of the few structural similarities that they share.
They are both vertebrates and they both know how to breathe in air. They both can lay eggs.
There are some principle differences between the two, like that birds have feathers, on the other hand, reptiles have scales or slimy/rough skin. Birds have beaks while reptiles have sharp teeth.