Reptile Adaptations

Reptiles have adapted in many different ways. They can hide in crevices, bluff to deter predators or swim like fish. Some even slither sideways!


California State University, Northridge biology professor Robert Espinoza studies how reptiles adapt to fluctuating temperatures. He says that although they are sensitive to heat, they don’t seem as phased by rising temperatures as humans might expect.

They Have Scales

Reptiles are a diverse group of animals that consists of four orders: Squamata (lizards, snakes, and worm-lizards), Crocodilia (alligators and crocodiles), Chelonia (turtles and tortoises), and Rhynchocephalia (tuatara). They share two characteristics with their ancient amphibian ancestors—scales and amniotic eggs.

Scales help reptiles evade predators, as well as harsh environments, such as hot deserts and dry savannahs. These scales, which are made of a tough keratin material, provide a layer of protection against scratches, bites, and other injuries. They also allow reptiles to retain moisture inside their skin by reducing water loss through evaporation.

In addition to their protective properties, scales help reptiles move across sand and other bare surfaces by allowing them to slip along the ground. They can also provide simple or complex coloration patterns that aid in camouflage and anti-predator displays. Some reptiles even use scales to protect their eyes from dust and other contaminants.

Although most reptiles have scales, they are not obligated to do so. There are a number of species, such as the smooth snake and leatherback sea turtle, that lack traditional scales. In these cases, a reptile’s scalelessness has to do with a genetic mutation that gives it a more unique appearance. Similarly, some chameleons and geckos have modified their scales into structures that resemble hair or feathers. This allows them to blend in with their surroundings and avoid being a meal for larger creatures.

They Have Skin

Reptiles’ skin is heavily keratinized, a trait that evolved as a response to life on land. This prevents water loss and makes it more resistant to abrasions as reptiles move across land surfaces.

It also helps them to maintain a stable body temperature (thermoregulation). Reptiles do not produce their own internal heat and must therefore absorb it from the environment. For example, a lizard can warm itself by basking in the sun. This is why most reptiles are diurnal and active at certain times of the day or night.

The skin also protects them from injury and disease. For instance, a savannah monitor’s overlapping scales protect it from the thorns and sharp spines of its prey. Scales are a common feature of many reptiles, but they may also take the form of plates and shields such as those found on the head of some snake species.

The skin has two layers, the epidermis and the dermis. The outermost layer is the stratum corneum, which consists of thick cuboidal cells that have undergone a process called keratinization. Below this is the intermediate zone, which contains cells in different stages of development. Finally, underneath the intermediate zone are the dermis’ chromatophores, which are responsible for the reptiles’ vibrant coloration. There are three types of chromatophores: xanthophores, which produce yellow pigments; erythrophores, which produce reddish-purple pigments; and iridophores, which produce iridescent colors that reflect light.

They Have Water-Repellent Skin

Reptiles evolved from water-dwelling ancestors and climbed onto land during the Paleozoic era, which eventually gave way to the Mesozoic era, where reptiles reigned supreme as snakes, lizards, turtles, crocodiles and birds. The dry skin of these reptiles is covered with keratin, which is water-resistant. This helps to keep hydration up and makes it more difficult for bacteria to damage the skin.

Many reptiles have adapted to the environments in which they live, including deserts. They can avoid extremes in aridity or heat by hiding under logs, rocks and leaves and are often active only during certain times of the day. In order to regulate their body temperature, they hide in cool shaded areas during the heat of the day and then shuttle between a sunny area and a cool spot to absorb as much heat as possible.

In addition, the kidneys of reptiles are specialized in that they conserve water by producing less urine. This helps to prevent dehydration, which could occur if the reptile was forced to drink too much liquid.

Tail displays are a common reptile behavior seen in pipe snakes (Anilliidae), shield tailed snakes (Uropeltidae) and coral snakes (Elapidae). This likely developed to divert a predator’s attention from the head to the more disposable tail, thus making them more vulnerable. A tuatara, the only living reptile from an extinct order, has a tail that can regrow, which may be due to an evolutionary adaptation that enabled it to survive a traumatic injury or disease.

They Have Kidneys

Reptiles are ectothermic animals that use their environment to regulate body temperature. They warm themselves by basking in sunlit areas, and they cool down by seeking shady spots or going underground. Because reptiles can’t self-regulate their internal temperatures as mammals and birds can, they are especially sensitive to fluctuating weather conditions.

Kidneys are an important part of the reptile osmoregulation system. Reptile kidneys excrete waste products, maintain normal concentrations of salt and water, regulate acid-base balance, produce hormones and vitamins, and conserve water. The kidneys of most reptiles consist of glomeruli designed to filter the blood, Bowman capsules that collect the filtrate and tubules that resorb most of the filtered fluid and excrete excess sodium and water. A loop of Henle is absent from the kidneys of most reptiles.

Marine reptiles have adapted their kidneys to conserve salt and excrete wastes that would otherwise be deposited in the lungs during extended dives. They also have adapted their lungs with a greater capacity for oxygen storage, allowing them to dive longer and deeper than terrestrial reptiles.

The kidneys of snakes are bean-shaped organs that sit on the back side of the abdomen. They are connected to a renal pelvis, which is a cup-like structure that collects urine produced by the kidneys and carries it to the bladder. The kidneys of all reptiles produce hypoosmotic urine, which consists of nitrogenous waste in the form of uric acid suspended in spheres complexed with proteins and either sodium (carnivorous diet) or potassium (herbivorous diet). The renal pelvis also contains a secretory tubule that produces urea.