WHAT TRAITS MAKE AN ANIMAL A REPTILE?
Hundreds of millions of years ago, reptiles became the first vertebrates to live on land. They are cold-blooded (ectothermic) animals i.e. they depend on outer heat sources (sun) to maintain their internal body temperature.
Reptiles bask in the sun to increase their body temperature and when they over-heat; they hide in burrows or in water to calm their body.
Reptiles are animals with a resilient, dry skin covered with horn-like scales. Some of the most commonly known reptiles are turtles, alligators, snakes, crocodiles, and lizards. All reptiles are vertebrates i.e. they have a backbone. They share some universal characteristics with other vertebrates but they display some unique sequence of characteristics that highly discern them from other vertebrates.
There are over 8,240 species of reptiles in the world, and they inhabit every continent on our planet (except Antarctica) and also live in oceans.
Reptiles have a central nervous system like all other vertebrates and a well advanced brain. Most reptiles possess two lungs, although some reptiles have lost their left lungs as per evolution. Also, quite a number of reptiles have a three chambered hearts, while some have four like mammals; four chambered reptiles include crocodiles and its immediate relations.
They have a digestive system this is very similar to that of other vertebrates, but it should be noted that there is quite a distinction in its guts and ducts of its urinary and sexual organs, quite unlike other vertebrates. The latter chamber to these aforementioned ducts and guts leads to an opening called the cloaca. Most reptiles pass out wastes from their kidney into this specially designed cloaca, particularly those inhabiting the sizzling, arid environments; moistures are then absorbed back into the body using the cloaca for use. Remainder wastes leave the body through a strapping opening in the cloaca which is situated at the base of the tail.
Almost all reptiles are carnivores; most reptiles often eat other smaller animals like fish and rodents. Most turtles and lizards are herbivores while some are omnivores.
Reptiles display extravagant courtship rituals before mating. Egg fertilization in female reptiles takes place internally i.e. the female’s eggs which are located in her ovaries are fertilized by the sperm of the male reptile within the female’s body. Turtles and crocodiles possess a lone penis, but their lizards and snakes counterparts have two and are called hemepenes, hemepenes are covered with creases and spines which hold the penis in place during mating. Reptiles with hemepenes use only one during mating, but species that copulate two or more times in progression, alternate their hemepenes.
The female lays her eggs in a shell that has a leathery covering which protects the egg. Some other reptiles like some snakes reproduce rather differently by having the ability to retain their eggs internally until they hatch, so instead of laying eggs, they birth fully developed young – this process is called ‘vivipary’. As for being parents, parental care is very rare in reptiles. The young are independent from the moment they’ve hatched.