Reptiles: Background

Colors plays a very important role in the life of iguanas and lizards. It helps to differentiate males and females, and when it is time a to attract a mate, the members of the iguana family communicate by showing bright colours and folds of skin. Another particularity that distinguishes iguanas is their covering of epidermal scales. In addition, like all reptiles, they are not capable of generating internal heat, so they depend on external factors to maintain their body temperature. For this reason, you will frequently see iguanaw lying stretched out in the sun. When it comes to their diet, most reptiles are carnivores, with the exception of some turtles, which are herbivores. Reptiles are also characterized byt their total independence from aquatic environments.

A Skin with Scales

Reptiles are vertebrates, meaning they are animals with a spinal column. Their skin is hard, dry and flaky. Like birds, most reptiles are born from eggs deposited on land. The offspring hatched fully formed without passing through a larval stage. The first reptiles appeared during the height of the carboniferous period in the Paleozoic era. During the Mesozoic era, they envolved and flourished, which is why this period is also known as the age of reptiles Only 5 of the 23 orders that existed then have living representatives today.

Internal Organs

The anatomy of reptiles enables them to to live on land. Thanks to their dry, scaly skin and their excretion of uric acid instead of urea, they minimize water loss. The heart distributes blood in a double circuit. Crocodiles were the first vertebrates to have a four-chambered heart; the separation of the ventricles is incomplete in all other reptiles. The lungs, developed beyond those of amphibians, contribute to cardiac efficiency by allowing for greater exchange of gases.

A Menu at Ground Level

Reptiles are basically carnivorous, even though some follow other regimens. Lizards usually feed on insects. Snakes usually feed on small vertebrates such as birds, rodents, fish, amphibians or even other reptiles. For many, the eggs of birds and other reptiles make a very succulent meal. The painted turtles is omnivorous: it eats meat and plants. Reptiles and other species are part of a larger food chain - animals eat other animals, preserving the equilibrium of the environment.

Reproduction

Most reptiles are oviparous. Some lay large numbers of eggs and then allow them to develop on their own, generally in well-protected nests or hidden under dirt or sand. Marine turles, especially green turtles, travel to the coast to lay their eggs in the sand, where they are left at the mercy of all who pass by. The females of other species, however, fiercely protect their offspring, staying near their nests for long periods of time to scare away potential predators.