Carl Linnaeus first initiated taxonomy as a science in the seventeen hundreds; reptiles included frogs, newts, and salamanders. Modern biologists classify organisms into domains, kingdoms, phyla, classes, orders, families, genera, and species. Select the reptiles for sale online.
Reptilia comprises lizards, snakes, turtles, and crocodiles; birds do not fall within this classification system or as good groupings.
Reptiles comprise approximately 11,500 living vertebrate animals (excluding birds ), with the dominant terrestrial animal kingdom. Reptiles include the most cold-blooded creatures, including all lizards, snakes, turtles, and crocodiles – thus deriving their name from the Latin word repent (meaning to creep or crawl).
Fossil evidence shows that reptiles are tetrapods – animals with four limbs that descend from four-limbed ancestors – as evidenced by fossil evidence. Hylonomus, the oldest actual reptile ever to exist during the Carboniferous period and thoroughly adapted for life on land, was one such reptile.
Modern reptiles can be divided into two major evolutionary lines, Archosauromorpha (crocodilians and their relatives) and Lepidosauromorpha (birds and lizards), with these branches diverging during the Permian period.
Seymouria, an archosaurian dinosaur-like creature, represents another evolution line and can be classified as amphibians or reptiles. However, some scientists consider it more closely related to amphibians than reptiles or birds. Some cladistic definitions say it falls within Captorhinomorpha, while other workers associate it with Amphibia under the Seymouria-Morphea clade.
Reptiles are air-breathing, cold-blooded vertebrates without feathers or hair that have four legs; many species include lizards, snakes, turtles, and some crocodilians, which may also be reptiles. Snakes and lizards fall under this classification, while those with two limbs (such as sauropsids ) fall under sauropsids (“squamates”).
Reptiles generally reproduce by oviparity, but certain species of lizards and extinct aquatic clades were viviparous. Viviparous reptiles reproduce by internal fertilization; eggs in their mother’s body stay inside until hatching occurs.
Reptiles often demonstrate thermoregulation behaviors such as basking in the sun or raising their heads from crevices to expose their lungs to air. Still, these displays could easily be misinterpreted as signs of disease or injury in these animals.
Reptiles can live almost anywhere, although some species prefer desert environments. Others thrive in tropical rainforests or mountain crags where predators may lurk; others, like amphibians and birds, inhabit aquatic environments.
Reptiles generally reproduce through egg-laying; however, snakes and some lizards are known to bear live young. Snakes and some lizards that act as live young are known as viviparous reptiles and carry them in protective pouches that store metabolic waste while protecting fetuses during gestation. Furthermore, these species have evolved to reproduce in dry terrestrial habitats.
As in amphibians, ectotherms use behavior and their environment to regulate their body temperatures; unlike mammals and birds, however, herps do not rely on metabolic processes to keep internal temperatures constant.
Herps can range from herbivorous species like land tortoises and the green iguana of Central and South America to carnivorous ones like the scleroglossan. Others, like scleroglossans, hunt fish or reptiles for sustenance; in many instances, herp populations don’t reproduce quickly enough for natural reproduction to keep pace. In many cases, their people must actively seek food as normal reproduction cannot keep pace.
Reptiles evolved to live on land. They are lung-breathing vertebrates with two pairs of limbs, scaled skin that is both horny and scaled for protection, and possessing three-chambered hearts. Most reptiles lay eggs while some lizards and snakes give birth live young – and all reptiles have large yolky eggs protected with leathery amnions that prevent drying out on land.
Modern reptiles are poikilothermic, meaning they cannot internally regulate their body heat as endothermic mammals and birds do. To maintain an even temperature level, modern reptiles use external heat sources, such as sunlight or ground temperatures, to stay warm during cold spells or immerse themselves in water as a superficial way to gain warmth.
Birds may appear different than their living reptilian counterparts. Still, scientists have determined that their ancestors were dinosaur-like animals that shared many features with reptiles, like being carnivorous and having a close kinship with alligators and crocodiles – which leads many people to consider their snakes as well.