Rebecca Nicholsonj age 10 of Atlanta GA
How are mammals different from reptiles?
The experts have sorted the kingdom of animals into a dozen or so huge tribes. Each tribe is sorted into a number of clans. Each clan is sorted into smaller families„ Miss Puss belongs to the Feline family of the Mammal clan Mr. Snake belongs to the Scaley family of the Reptile clan. Both belong to the vast tribe of backboned animals the Vertebrates.
All mammals and reptiles have backbones. Even the turtles. who is a reptile. has a backbone inside his coat of armor. Some vertebrates must breathe under water. such as the fish. But both the reptiles and the mammals are air breathers. Even the ocean‑.going whale comes up for air;
There are other likenesses which make the sorting of mammals and reptiles difficult. In a dim light you might mistake a little lizard for a mouse. They are about the same size. Each has four legs. though reptile legs are wide spread and close to the ground. Each has a tail and two bright eyes. Either one may be chasing a cockroach. But the mouse is a mammal. the lizard a reptile.
A reptile may be without legs. The snake manages without legs. A mammal may be without. or almost without a tail. The orangutan is a mammal. All mammals have four limbs but not so all reptiles. All reptiles have tails! but not so all mammals.
There are others. more certain ways to sort the mammals from the reptiles. You could tell better if you held the mouse in one hand and the little lizard in the other. The‑mouse has a furry coat. Almost all the mammals wear coats of fur. hair or fleece. The whale. who lives in the sea. is one of the few mammals without a warm coat. The lizards. however. has a bare skin. Reptile skin is thick and often scaley like the crocodiles.
On a cool day the mouse would feel warmer to hold than the lizard. On a hot day the lizard might feel warmer to the touch. Mammals can use some of their food to make body heat. They can also sweat to cool off and keep their bodies at an even temperature. Reptiles cannot do this. They are warmed by the air around them. Mammals are called warm blooded and reptiles cold blooded animals.
The big differences however lies with Mama Mammal and Mama Reptile. Mama Mammal.. from whale to mouse feeds her babies on mother’s milk. In all the animal kingdom only the mother mammals can do this. Most reptiles lay eggs. As a rules they are not good mothers. They let their babies hatch and fend for themselves.
True certain reptiles give birth to live babies. Garter snakes do not lay eggs. They are born as little snakes. But Mama Garter Snake cannot nurse her babies after they are born. Mrs. Platypus is a mammal and she lays eggs. But when the babies hatch they feed on mother’s milk Like most mammals she is a kind and careful mother.
The fur coats make the mammals very different from the reptiles. So does their warm blood. But the biggest difference is in mother. love. This careful tending of the young has helped the mammals to develop into the most advanced group in the whole animal kingdom.