All About Reptiles — Science Lesson

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All About Reptiles

Reptiles are cold-blooded vertebrates that rely on their environment to regulate body temperature. They are found on every continent except Antarctica, in habitats ranging from tropical jungles to dry deserts. Scientists classify living reptiles into four main groups: Crocodilia, Rhynchocephalia, Squamata, and Chelonia.

Crocodilia includes crocodiles, alligators, caimans, and gharials. These large, powerful reptiles are among the oldest animal lineages on Earth, with fossil relatives dating back over 200 million years. Unlike most reptiles, crocodilians have a four-chambered heart and provide parental care for their young. Chelonia — turtles and tortoises — are distinguished by their hard protective shells, which are extensions of the skeleton.

Squamata is the largest reptile group, containing all lizards, snakes, and worm lizards. Snakes evolved from lizard ancestors and lost their legs over millions of years. They move by slithering and use highly flexible jaws to swallow prey whole. Worm lizards are burrowing animals that resemble earthworms. Rhynchocephalia contains only the tuatara, a lizard-like reptile found only in New Zealand that has changed very little in 200 million years.

All reptiles breathe air through lungs, lay eggs on land (or give birth to live young), and have scaly skin that prevents water loss. Most reptiles are carnivores, though some lizards and tortoises are herbivores. Reptiles play important roles in ecosystems as both predators and prey, helping to control insect and rodent populations.

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