Class REPTILIA
This class consists of turtles, snakes, lizards, and crocodiles.
ECOLOGICAL ROLE
Reptiles play a vital role in the food chains of most ecosystems and are in some cases a keystone species, which without can have devastating effects on the populations of other organisms. Reptiles consume rodents and insects which aids in the control of these organisms.
Reptiles play a vital role in the food chains of most ecosystems and are in some cases a keystone species, which without can have devastating effects on the populations of other organisms. Reptiles consume rodents and insects which aids in the control of these organisms.
MOVEMENT STRUCTURES/ TYPE
Although not all reptiles have legs, many of them use their four legs to walk, such as crocodiles, alligators, turtles, lizards and tuataras. Several reptiles can actually glide through the air, as if they're flying. For example the flying tree snake flattens out its body to soar from one tree branch to a lower one, and the flying geckos of Southeast Asia have a number of little flaps on their body, tail, legs and head that help them glide. Snakes slither by twisting and bending their bodies in an S shaped pattern along the ground. Many turtles, alligators and crocodiles spend majority of their lives in water. Turtles often have wide feet that they use to push them through the water, Alligators and crocodiles have strong long tails that help propel and steer their bodies through the water.
Although not all reptiles have legs, many of them use their four legs to walk, such as crocodiles, alligators, turtles, lizards and tuataras. Several reptiles can actually glide through the air, as if they're flying. For example the flying tree snake flattens out its body to soar from one tree branch to a lower one, and the flying geckos of Southeast Asia have a number of little flaps on their body, tail, legs and head that help them glide. Snakes slither by twisting and bending their bodies in an S shaped pattern along the ground. Many turtles, alligators and crocodiles spend majority of their lives in water. Turtles often have wide feet that they use to push them through the water, Alligators and crocodiles have strong long tails that help propel and steer their bodies through the water.
BODY COVERING; CELL LAYERS; LEVEL OF ORGANIZATION; PROTECTION
All reptiles have, or did have, horny epidermal scales made of a particular kind of protein, are tetrapods (four limbs) with 5 clawed toes, skulls, lungs, and 3 or 4 chambered hearts. Their skin is covered in a horny epidermis, making it watertight and enabling them to live on dry land. Their bodies are protected by scales or scutes some with bony bases forming armor. In lizards and snakes their entire skin is covered in overlapping epidermal scales. The scales of turtles and crocodiles are dermal rather than epidermal and is composed of scutes. They have bodies covered with scales made of keratin. Turtles bodies are encased in a hard shell composed of the same material. Most reptiles outer layers can camouflage according to their surroundings. Tactics are also used to ward off predators or to give warning of danger. Some species display brightly colored body parts such as tongues, loud hissing, biting attempts, and in rattlesnakes, the rattling of the tail. Some reptiles such as snakes and lizards are venomous. Venomous snakes have two fangs in their upper jaw that consist of grooves that send the venom down the tooth and into the prey. Venomous lizards have venom in their lower jaw and deliver it through grooves in their teeth.
All reptiles have, or did have, horny epidermal scales made of a particular kind of protein, are tetrapods (four limbs) with 5 clawed toes, skulls, lungs, and 3 or 4 chambered hearts. Their skin is covered in a horny epidermis, making it watertight and enabling them to live on dry land. Their bodies are protected by scales or scutes some with bony bases forming armor. In lizards and snakes their entire skin is covered in overlapping epidermal scales. The scales of turtles and crocodiles are dermal rather than epidermal and is composed of scutes. They have bodies covered with scales made of keratin. Turtles bodies are encased in a hard shell composed of the same material. Most reptiles outer layers can camouflage according to their surroundings. Tactics are also used to ward off predators or to give warning of danger. Some species display brightly colored body parts such as tongues, loud hissing, biting attempts, and in rattlesnakes, the rattling of the tail. Some reptiles such as snakes and lizards are venomous. Venomous snakes have two fangs in their upper jaw that consist of grooves that send the venom down the tooth and into the prey. Venomous lizards have venom in their lower jaw and deliver it through grooves in their teeth.
SUPPORT
All reptiles have a long vertebral column to protect their nerve cord and a strong skeletal system with a sturdy rib cage to protect vital organs.
All reptiles have a long vertebral column to protect their nerve cord and a strong skeletal system with a sturdy rib cage to protect vital organs.
OBTAINING NUTRIENTS
Many reptiles are carnivores. Some lizards and snakes eat mainly insects, spiders, worms and other invertebrates. Large snakes often eat mammals, amphibians, fish, birds and other reptiles. Many snakes and lizards also eat eggs. Some reptiles such as certain turtle and lizard species eat plants. All reptiles have mouths and jaws lined with teeth through which they eat from. Many reptiles hunt by hiding or lying very still and then lunge out and grab their prey. Many reptiles snap their mouths around the prey and swallow it. Crocodiles and alligators clamp their jaws around large prey, drag them into the water and tear off chunks of flesh. Many snakes inject venom into their prey to kill or knock it out.
Many reptiles are carnivores. Some lizards and snakes eat mainly insects, spiders, worms and other invertebrates. Large snakes often eat mammals, amphibians, fish, birds and other reptiles. Many snakes and lizards also eat eggs. Some reptiles such as certain turtle and lizard species eat plants. All reptiles have mouths and jaws lined with teeth through which they eat from. Many reptiles hunt by hiding or lying very still and then lunge out and grab their prey. Many reptiles snap their mouths around the prey and swallow it. Crocodiles and alligators clamp their jaws around large prey, drag them into the water and tear off chunks of flesh. Many snakes inject venom into their prey to kill or knock it out.
RESPIRATION
All reptiles breathe using lungs. Aquatic turtles have developed permeable skin and some species even have gills, but even with these adaptations, breathing is never fully accomplished without the lungs.
All reptiles breathe using lungs. Aquatic turtles have developed permeable skin and some species even have gills, but even with these adaptations, breathing is never fully accomplished without the lungs.
CIRCULATION
All reptiles are cold-blooded and absorb heat from their environment (ectothermic). Most reptiles have a closed circulatory system with a three chambered heart consisting of two atria and one ventricle. They usually have one pair of aortic arches. There isn't much mixing of oxygenated and deoxygenated blood in the heart.
All reptiles are cold-blooded and absorb heat from their environment (ectothermic). Most reptiles have a closed circulatory system with a three chambered heart consisting of two atria and one ventricle. They usually have one pair of aortic arches. There isn't much mixing of oxygenated and deoxygenated blood in the heart.
EXCRETION
The digestive system of reptiles includes the mouth, tongue, and its salivary glands, teeth, the esophagus, the stomach and the intestine that ends in a cloaca. Land dwelling reptiles such as snakes and lizards excrete nitrogenous wastes in a pasty or dry form. Reptiles use two small kidneys as tools for excretion.
The digestive system of reptiles includes the mouth, tongue, and its salivary glands, teeth, the esophagus, the stomach and the intestine that ends in a cloaca. Land dwelling reptiles such as snakes and lizards excrete nitrogenous wastes in a pasty or dry form. Reptiles use two small kidneys as tools for excretion.
RESPONSE
The reptilian nervous system consists of the same basic elements as the amphibian brain, although the reptile cerebrum and cerebellum are larger. They have highly developed sense organs besides the fact that snakes don't have external ears. A snake's tongue includes sensitive smell sensors, and also have a special organ called the jacobson’s organ that allows snakes to find mates and identify food and predators. Crocodiles have sensory pits in their lower and upper jaw that contains nerve fibres to detect disturbances in the water. They have twelve pairs of cranial nerves like humans, and their spinal cords extend to the tip of their tails. Reptiles have keen vision that is typically adapted to daylight conditions with color vision and advanced depth perception.
The reptilian nervous system consists of the same basic elements as the amphibian brain, although the reptile cerebrum and cerebellum are larger. They have highly developed sense organs besides the fact that snakes don't have external ears. A snake's tongue includes sensitive smell sensors, and also have a special organ called the jacobson’s organ that allows snakes to find mates and identify food and predators. Crocodiles have sensory pits in their lower and upper jaw that contains nerve fibres to detect disturbances in the water. They have twelve pairs of cranial nerves like humans, and their spinal cords extend to the tip of their tails. Reptiles have keen vision that is typically adapted to daylight conditions with color vision and advanced depth perception.
REPRODUCTION
Reptiles generally reproduce sexually through internal fertilization, although asexual reproduction occurs within some snake and lizard species. Most females lay eggs, but some species give birth. All reproductive activity occurs through the cloaca, which is the also where waste is eliminated from. Most reptiles have reproductive organs which are usually stored inside the body. In turtles and crocodiles, the males have a single penis whereas snakes and lizards possess a pair of hemipenes. They lay amniotic eggs covered with leathery or calcareous shells, meaning their eggs are protected by an extra membrane, the amnion. There is typically no parental care for young but some crocodiles and snakes do protect and care for their young.
Reptiles generally reproduce sexually through internal fertilization, although asexual reproduction occurs within some snake and lizard species. Most females lay eggs, but some species give birth. All reproductive activity occurs through the cloaca, which is the also where waste is eliminated from. Most reptiles have reproductive organs which are usually stored inside the body. In turtles and crocodiles, the males have a single penis whereas snakes and lizards possess a pair of hemipenes. They lay amniotic eggs covered with leathery or calcareous shells, meaning their eggs are protected by an extra membrane, the amnion. There is typically no parental care for young but some crocodiles and snakes do protect and care for their young.