A Brief Evolution of Reptiles
Evolution is the theory that all plants and animals developed by gradual changes to previous forms of life. Charles Darwin and A.R. Wallace created the first concept of evolution, but today their theory has been further worked out to fill in the gaps between species changes. In theory first there were fish, amphibians, reptiles, birds, and then mammals. Looking at the reptile aspect of evolution, I'm going to start with fish up to the more evolved reptiles.
Thinking about evolution as a child's storybook, you can envision a school of fish becoming bored in waters, which were becoming overcrowded and food becoming low. The school decides to hope on land, some make it, some don't. Finding that there was much more available food on land, the fish decide to stay longer and longer. Eventually, only using water for food and breeding, thus creating the amphibian, which after time decide that the water thing just isn't cutting it, there's more out there than just water. So, because they normally would have to spend much of their time around pools of water, the amphibians, decided to venture further away. Already having, laying eggs, the amphibians slowly began developing harder, more calcified eggs, that were able to sustain their own water without becoming dehydrated without being in water. This let up much more opportunities for the amphibians, now known as reptiles.
The evolution of reptiles did not happen over a period of a few years, but rather millions of years. Slowly, evolving more and more characteristics that would allow them to breed, multiple, and survive, on land. Water was no longer a source of life, but a food source and a source of hydration.
Once solely on land, the new reptile group of animal, began to evolve into different orders. Each order having different characteristics allowing them to survive in different environments. Jungle snakes would not be able to survive in the desert heat of the Sahara, and, vice versa, desert lizards would not be able to survive in humidity of the Amazon.
There are four orders to classify all reptiles. The Squamata includes the lizards and snakes, making it the largest of the four orders. The Chelonia includes all turtles and tortoises, wild and captive bred. Crocodiles, alligators, caimans, and gavials, are all grouped in the Crocodilla order. The fourth order, the Rhynchocephalia, is composed of only one member, the living fossil, also known as the tuatara.
Reptiles have come a long way throughout the evolution process. Now, with the ability to live, breed, and survive in captivity, to include zoos, sanctuaries, and personal homes.
I want to make it clear that this brief summary is all scientific theory, and not 100% facts.
Pictures can be found at Yahoo images.