Many people overlook that dinosaurs were reptiles, as are tortoises and turtles. Frogs are often lumped into the same category while they are, in fact, amphibians.
Reptiles evolved from amphibians because of their necessity to learn to adjust to life on land. This brought about the need for legs and lungs to breathe air. Yet snakes are legless, able to crawl along with their magnificent bodies. The scaly reptile skin was necessary to protect the bodies from the rough surface of the ground, much different from the smooth water the amphibians were used to.
Science has described over 7,000 species of reptiles, even going so far as to claim birds as a part of the reptile group because of the inherited characteristics such as their skeletons, internal organs, and DNA. There is a distinction besides feathers, though. Birds are endotherms, meaning they must have food for energy to keep warm. Other reptiles are ecotherms which need an outside heat source to help them retain proper body temperature.
Crocodiles are in the second oldest group of reptiles, perhaps resembling the dinosaur relatives more than any other reptile group. Although, the turtle is the winner of the oldest proven reptile group, even older than the dinosaurs!
There are two groups of turtles, one group fares best on land and the other in water. The one that fares best on land is the terrestrial tortoise.
Success in keeping a reptile for a pet depends much on your climate. You can forget sticking your pet snake, turtle, or lizard outside in a cage or pen or aquarium if you live in a cold climate. Keeping the pet in a controlled temperature is essential to its survival. Digestion depends on the right temperature and so does the animal's ability to move around successfully.
It may seem cute to see that little turtle basking in the sun on a log in a pond. But the reptile needs the heat to stay alive. Too much heat is also as bad as too little.
Maybe the turtle's ability to live for so many centuries when other animals perished is because of its outstanding life span. A turtle can live to 100 years old if the conditions are right!
Old temples have been discovered in Africa with snakes carved into the walls, giving pythons a sacred quality over the many years of its existence. But the boas have been known to live over forty years at a time in zoos! Anacondas have been feared in South America for a long time. Any snake that can grow to over 35 feet deserves a wide berth!
An interesting reptile that's been around a long time is a native of Madagascar. The chameleon exists in 120 different known types. Oustalet's chameleon is about the size of a small cat. It would give a domestic feline a definite scare to walk upon one of those! On the other end of the size spectrum, the Dwarf Brookesia, also a native of Madagascar, is small enough to stand on the tip of a finger.