Leapin' Lizards
With more than 4,000 types of lizards, few characteristics are shared by all of them. All lizards have overlapping scales and small heads compared to their bodies. They have external ears and movable eyelids. Most lizards have four legs with claws on each toe, but some lizards have two or no legs. Most lizards are omnivorous, but some are carnivorous or herbivorous. Lizards range in size from 1.5 centimeters (0.6 inch) to 3 meters (10 feet) in length. Types include geckos, chameleons, anoles, skinks, bearded dragons, iguanas, monitors, Gila monsters and Komodo dragons.
The Shelled Variety
Chelonians are turtles, tortoises and terrapins. The large shell covering a chelonian̵7;s back distinguishes the group from other reptiles. Chelonians do not have any teeth, instead using their beak-shaped jaw to bite plants, insects or fish. Chelonians range from about 8 centimeters (3 inches) to 2.5 meters (8 feet) in length. All turtles are strong swimmers, even the species with webbed feet instead of flippers. Turtles spend most of their time in the water, but turtles with feet will also burrow in the mud and climb on their surroundings. Tortoises live in hot, dry climates where they use their rounded legs to find shelter when it is too hot. Terrapins live on both the land and the water, particularly in wetlands.
Crocs and Gators
Crocodilians include crocodiles, alligators, caimans and gharials. Crocodilians are distinguished from other reptiles because of their large muscled tail, internal ears and lack of overlapping scales. Crocodilians are tropical and subtropical carnivores that range in size from 1.5 to 6 meters (5 to 20 feet). Crocodiles have a narrow, triangular snout and live in saltier environments. Alligators have a broader, U-shaped snout and are more common in freshwater. Caimans are small alligators found in Central and South America. Gharials use their very narrow snouts with a bulbous tip to eat fish in the rivers of India.
Snake Species
Snakes have no feet, but unlike footless lizards, snakes have no eyelids or external ears. Snakes are carnivorous and found in nearly every habitat, including the sea. Their flexible bodies lend to their slithering motion and allow them to spread out to draw in heat and curl up to conserve the heat. The 3,000 species of snakes range in length from 11 centimeters (4.5 inches) to 10 meters (33 feet). Some species are harmless and small, but others are venomous or constrictors. Species include vipers, anacondas, pythons, garter snakes, garden snakes, corn snakes and rattlesnakes.