Reptiles are a class of animals that includes turtles and tortoises, snakes, lizards, crocodiles and alligators, and tuataras. There are over 8,000 species of reptiles in the world, inhabiting every continent except Antarctica. Reptiles share many traits with other classes of animals, but they are the only animals that have this combination of traits: skin covered with a sheet of scales; self-regulated body temperature; and young that look like miniature adults (most hatched from eggs, but some born live). Reptiles are considered to occupy an evolutionary position between amphibians and the warm-blooded vertebrates.
No Moisturizer Necessary
Reptiles have dry scaly skin rather than hair or feathers. But they don’t need moisturizer! Their special covering actually helps them hold in moisture and lets them live in dry places.
Reptile scales are connected in a “sheet,” which is the outermost layer of skin. Every so often, this layer of skin is shed and replaced. In some reptiles the skin flakes off in chunks. In snakes, the skin is usually shed in one piece. You may not think of turtle and tortoise shells as being scaly, but they are! They’re shells are complex structures made up of bones and scales that develop from the outer layer of skin. It’s natural body armor!
Heating Up and Cooling Down
Reptiles, like amphibians, are ectotherms ( “cold-blooded”). This means that they can’t produce sufficient internal heat to maintain a constant body temperature. Instead, reptiles are responsible for regulating their own body temperature. When it’s cold outside and they need to warm up, they often bask in the sun to raise their body temperature. When it’s too cold to bask, reptiles may brumate. This means they’re in a hibernation-like state, but they may have periods of wakefulness and even drink when necessary. When it’s hot outside, reptiles spend much of the time burrowing during the day to cool off and become active only at night.
At birth, young reptiles are miniature versions of their parents- though sometimes with different coloring. This is very different from amphibians (like frogs and salamanders), which undergo a drastic change from larvae to adults. Most reptiles — including all turtles, crocodiles, and alligators — lay eggs. But other reptiles — about one out of five types of lizards and snakes — bear live young.