Mammals and reptiles are two of the five classes of vertebrates. There are more than 5000 species of mammals including bears, whales, wolves, apes, bats, and even humans.
Reptiles are a more diverse group than mammals with more than 8000 species including lizards, crocodiles, snakes, turtles, and so on.
Mammals vs Reptiles
The difference between mammals and reptiles is that mammals are warm-blooded animals that have skin generally covered by their hair. Mammals nourish their kids with milk secreted from the mammary glands. On the other hand, reptiles are cold-blooded animals that have scaly and dry skin. They lay shells like eggs on the land.
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Mammals are one of the five classes of the vertebrate group. Mammals are warm-blooded animals and have mammary glands from which milk is secreted to feed their offspring.
They have bodies covered by hair. Hairs in the body help mammals to survive cold climates. Although whales don’t have hair in their bodies.
Reptiles are another type of animal class of the vertebrate group. Reptiles are cold-blooded animals and depend on their surroundings to warm up their body.
Reptiles have dry skin which is covered either with horny plates or scales. They breathe by using their lungs. Most of the reptiles lay the egg on the ground and eat other animals for survival.
Comparison Table
| Parameters of Comparison | Mammals | Reptiles |
|---|---|---|
| Skin | Mammals have hair all over their body. They also have sweat glands on their skins. | Reptiles don’t have hair on their body. Rather, they have scales, which are quite different from fish scales, that arise in the epidermis (upper layer of the skin) instead of in the dermis layer of the skin. |
| Teeth | Mammals have specialized teeth, like morals which are used for grinding food, and canines which are used for tearing through the meat. They grow only two sets of teeth throughout their lives. | Reptiles have uniform shaped teeth, though it varies in size. Reptiles continuously grow teeth throughout their lives. |
| Jaw and ear bones | Mammals have a lower jaw bone firmly attached to the skull. The lower jaw bone is one continuous bone. Biologists believe that the lower jawbones of the reptilian jaw have evolved into the three middle ear bones of mammals. | The lower jaw of the reptiles has multiple bones. But they have only one ear bone. |
| Cardiovascular system | The mammals’ heart has four chambers- two atria and two ventricles. Ventricles deliver oxygenated blood to the body organs and atria direct blood to the lungs to re-oxygenate the body. As a result, the mammalian body always remains warm. | The reptilian heart consists of three chambers- one atrium and two ventricles. Unlike mammals, reptiles are cold-blooded. They need to depend on the environment to warm their body. |
| Reproduction | All-female mammals give birth to live young. They have mammary glands that secrete milk to feed their offspring. | Most of the reptiles lay eggs. Female reptiles don’t have mammary glands. They generally abandon their young after hatching. |
What is Mammals?
Mammals are one of the five classes of vertebrate animals. Mammals give birth to live young and feed their young with the milk secreted from their mammary glands.
Besides these characteristics, mammals are distinguished from other classes by some other characteristics. They have hair covered all over their body.
However, whales don’t have hairs in their body. They also have sweat glands on their skins.
Mammals have a lower jaw bone firmly attached to the skull. The lower jaw bone is one continuous bone. Biologists believe that the lower jawbones of the reptilian jaw have evolved into the three middle ear bones of mammals.
Mammals have specialized teeth, like morals which are used for grinding food, and canines which are used for tearing through the meat. They grow only two sets of teeth throughout their lives.
The mammals’ heart has four chambers- two atria and two ventricles. Ventricles deliver oxygenated blood to the body organs and atria direct blood to the lungs to re-oxygenate the body. As a result, the mammalian body always remains warm.
The Mammalia class has produced a diverse habitat and form. The Mammalia class is distributed worldwide. There are over 5500 species of mammals arranged in almost 125 families.
The most numerous in existing mammals are rodents. It is generally accepted that mammals are the most adaptable compared to any other animal class (insects and arachnids are exceptions).
What is Reptiles?
Reptiles are another class of vertebrate group that have amniotic development, epidermal scales covering all over their body, and internal fertilization.
The major living reptile groups- the tuatara, the turtles, snakes, crocodiles, and lizards- account for more than 8700 species.
Reptiles have uniform shaped teeth, though they vary in size. Reptiles continuously grow teeth throughout their lives. The lower jaw of the reptiles has multiple bones.
But they have only one ear bone. The reptilian heart consists of three chambers- one atrium and two ventricles. Unlike mammals, reptiles are cold-blooded. They need to depend on the environment to warm their body.
Most of the reptiles lay eggs. Female reptiles don’t have mammary glands. They generally abandon their young after hatching. Reptiles don’t have hair on their body.
Rather, they have scales, which are quite different from fish scales, that arise in the epidermis (upper layer of the skin) instead of in the dermis layer of the skin.
Reptiles generally lay eggs that are covered with leathery or calcareous shells. They feed their offspring generally through hunting. Some of the reptiles abandon their offspring after hatching.
Some of the reptiles use their tails as a defence mechanism. Snakes use venoms to the enemy as a defence mechanism.
Main Differences Between Mammals and Reptiles
- Mammals have hair all over their body. They also have sweat glands on their skins. On the other hand, reptiles don’t have hair on their body. Rather, they have scales, which are quite different from fish scales, arise in the epidermis (upper layer of the skin) instead of in the dermis layer of the skin.
- Mammals have specialized teeth, like morals which are used for grinding food, and canines which are used for tearing through the meat. They grow only two sets of teeth throughout their lives. Reptiles have uniform shaped teeth, though they vary in size. Reptiles continuously grow teeth throughout their lives.
- Mammals have a lower jaw bone firmly attached to the skull. The lower jaw bone is one continuous bone. Biologists believe that the lower jawbones of the reptilian jaw have evolved into the three middle ear bones of mammals. The lower jaw of the reptiles has multiple bones. But they have only one ear bone.
- The mammals’ heart has four chambers- two atria and two ventricles. Ventricles deliver oxygenated blood to the body organs and atria direct blood to the lungs to re-oxygenate the body. As a result, the mammalian body always remains warm. On the contrary, the reptilian heart consists of three chambers- one atrium and two ventricles. Unlike mammals, reptiles are cold-blooded. They need to depend on the environment to warm their body.
- All-female mammals give birth to live young. They have mammary glands that secrete milk to feed their offspring. Most of the reptiles lay eggs. Female reptiles don’t have mammary glands. They generally abandon their young after hatching.
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Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.
