Reptiles have a variety of morphological and physiological traits. These include: a single bone where the skull attaches to the first vertebra; a single auditory bone, the stapes, that transmits vibrations from the eardrum; and thick, scaly skin.
파충류샵They are cold-blooded and regulate their body temperature through behaviour, such as basking in the sun to warm up or seeking shade to cool down. They also have highly developed lungs.
Snakes
Snakes inspire fascination and feelings of fear in equal measure, but they also play an important role in the natural environment and food web. These long, limbless predators use their senses of sight, smell and hearing to locate prey and ambush their targets. Some snakes inject a lethal dose of modified saliva into their prey to paralyse and kill them.
Like all squamates, snakes are ectothermic amniote vertebrates covered in overlapping scales. They are also known for their powerful muscles, which enable them to swallow prey much larger than their heads (cranial kinesis). Their skeletons are almost always radially compressed, with the exception of henophidian snakes that retain vestiges of pelvic girdle and rear limbs.
Reptiles have a specialized skin that is covered in rough horny layers of scales or bony plates, and is composed of keratin—the same substance found in hair and nails. This tough, dry skin helps them to maintain a constant body temperature by reflecting the heat of the sun or other sources of light back to the skin. Reptiles shed their skin regularly throughout their lives, but this process is most frequent during adolescence.
Unlike birds, mammals and amphibians, the vast majority of reptile species are not at risk of going extinct. However, their conservation challenges are complex. In many regions, they face a combination of human activities and habitat destruction. They are also impacted by global warming and regional weather extremes, which can alter their habitat and prey populations.
Lizards
Lizards are the largest reptile group, ranging from tiny chameleons and geckos to giant monitors and komodo dragons. Their body types and habitats are highly variable, but a common feature is that most species lay eggs and give birth to live young. Like all reptiles, lizards are cold-blooded and have a naturally low metabolic rate to conserve energy. They also lack the ability to sweat, so they regulate their internal temperature through other means. These include basking in the sun, burying themselves in sand or earth, and changing their skin color to absorb more sunlight or reflect less of it.
They use their tongues to smell airborne scent particles, and some even have special sensory cells on the roof of their mouths for receiving sound. Many lizards can even change the shape of their tongues to better fit the terrain or hunt for prey.
Despite these adaptations, lizards are in decline worldwide. They are often targeted for the pet trade, and their numbers have suffered from habitat destruction. However, the recent international commitment to reverse the worldwide trend of biodiversity loss, including specific targets for key sites and specialized policies for threatened reptiles, bodes well for their future. In addition, lizards serve as natural insect-control agents in their habitats and can be beneficial to humans by keeping populations of harmful pests under control.
Turtles
Turtles have been around for over 250 million years, making them one of the oldest reptiles and the only vertebrates that have been around as long as mammals. Their closest ancestor, Eunotosaurus, was a land-dwelling reptile that shared some of the basic characteristics of modern reptiles, such as elongated ribs and a broad head.
Turtle shells are fused to the animal’s ribs and cover hard scales called scutes. Like other reptiles, turtles are ectothermic, and depend on their environment to regulate body temperature.
They have a closed circulation with a three-chamber heart that includes two atria and one variably partitioned ventricle. This allows them to shunt deoxygenated blood to the heart or oxygenated blood to their lungs, which lets them breathe underwater for longer periods of time (though most sea turtle species can only dive to about 290 m, or 960 ft).
Most turtles have serrated jaws that they use to crush their prey and stiff downward projections in their throats, called papillae, that keep their meals from slipping back out of their mouths. But some sea turtles, including hawksbills and leatherbacks, have a unique ability to swim down to depths of more than 1,000 m, or 3,900 ft.
Turtles are classified in the order Testudines, which is a subclass of the class Anapsida, or amniotes. The only other animals in this group are amphibians. In addition, turtles have a hard cartilage-based shell that extends from their ribs and acts as a protective shield. They also lay shelled eggs, and are able to move on land using flippers. They are known in many languages and countries as tortoises, terrapins, and turtles; variations in the name reflect regional dialects and do not represent differences in biological characteristics.
Chameleons
Chameleons are known for their unique appearance, and they’re easily recognizable by their large eyes, movable arms and legs, and ability to change colors. They use color to communicate with other chameleons and their predators. They also use it to signal their moods or to attract a mate.
These scaly reptiles are one of the most diverse species on Earth, and they live in a wide range of habitats, including forests, deserts, and mountain areas. They usually stay in trees or bushes, but they can crawl along the ground as well. They use their prehensile tails to wrap around branches and their large toes to cling on. They typically live solitary lives, but male and female chameleons sometimes interact during mating season.
The eyes of a chameleon are its most distinctive feature. It can rotate its eyes independently of each other, enabling it to see in two different directions at once. It can also quickly focus and enlarge its eyes to view objects close-up, like a camera lens.
Most chameleons are sit-and-wait predators, observing prey from their perches before launching a surprise attack. They can shoot their sticky tongues out to distances up to twice their body length to catch insects, and they can grab prey in 0.07 seconds (the smaller the chameleon, the faster and farther its tongue can be propelled). The lizards also have a special gland that releases chemicals that change their skin’s texture and color, adding to their camouflage.