information on Reptiles
Groups
Turtles are among the most ancient of the reptiles alive today and have changed little since they first appeared some 200 million years ago. They have a protective shell that encloses their body and provides protection and camouflage. Turtles inhabit terrestrial, freshwater, and marine habitats and are found both in tropical and temperate regions.
Squamata are the most diverse of all the reptile groups and include lizards, snakes and worm-lizards. There are nearly 7,600 species of squamates alive today. The earliest squamate fossils date back to the beginning of the Jurassic Period. Squamates shed their skin periodically and have jointed skulls and jaws that enable them to capture larger prey and bite with great power.
Crocodilians first appeared during the late Cretaceous Period, about 84 million years ago. The group includes alligators, crocodiles, gharials, and caimans. Crocodiles are the closest living relatives to birds.
Tuataras are a group of reptiles that are lizard-like in appearance but they differ from members of the Order Squamata in that their skull is not jointed. Tuataras were once widespread but today only two species of remain. Their range is now restricted to just a few islands in New Zealand.
Squamata are the most diverse of all the reptile groups and include lizards, snakes and worm-lizards. There are nearly 7,600 species of squamates alive today. The earliest squamate fossils date back to the beginning of the Jurassic Period. Squamates shed their skin periodically and have jointed skulls and jaws that enable them to capture larger prey and bite with great power.
Crocodilians first appeared during the late Cretaceous Period, about 84 million years ago. The group includes alligators, crocodiles, gharials, and caimans. Crocodiles are the closest living relatives to birds.
Tuataras are a group of reptiles that are lizard-like in appearance but they differ from members of the Order Squamata in that their skull is not jointed. Tuataras were once widespread but today only two species of remain. Their range is now restricted to just a few islands in New Zealand.
Species
Of the four groups of reptiles, the squamates (lizards, snakes and worm-lizards) are the most diverse. There are nearly 7,600 species of squamates, including about 2,900 species of snakes, 4,500 species of lizards, and 158 species of amphisbaenians. Turtles is the second most diverse group of reptiles, with about 294 species. There are 23 species of crocodilians and 2 species of tuataras.
Features
Reptiles are cold-blooded or ectothermic which means they do not generate their own, internal heat. This is one of the main ways reptiles differ from other animal groups such as mammals and birds (both of which are endothermic, meaning they are able to produce their own internal heat). Reptiles must rely on their environment for warmth. That's why they bask in the warmth of the sun during the day and seek shelter at night to avoid cold. Reptiles also must avoid overheating, so if daytime temperatures climb too high, they must seek shelter to avoid absorbing too much heat.
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