Reptile Quiz: Test Your Knowledge on Reptiles!

Reptiles are a group of animals that include sauropsids, excluding birds. Living reptiles include turtles, crocodilians, squamates, and rhynchocephalians, and the Reptile Database includes about 11,700 species. Birds are considered a separate class to reptiles in the traditional Linnaean classification system, but modern classification systems include birds within Reptilia. The earliest known proto-reptiles originated around 312 million years ago, and the two largest lineages of reptiles diverged near the end of the Permian period. Reptiles are tetrapod vertebrates and most are oviparous, with some species of squamates being viviparous. Extant reptiles range in size from a tiny gecko to the saltwater crocodile. The classification of reptiles has been a topic of debate throughout history, and the term "reptile" is paraphyletic. The phylogenetic taxonomy defines reptiles as a monophyletic node-based crown group containing turtles, lizards and snakes, crocodilians, and birds, their common ancestor, and all its descendants. The placement of turtles has historically been highly variable, and as of 2013, molecular work has placed turtles within the diapsids. The earliest amniotes evolved from advanced reptiliomorphs around 310-320 million years ago, and the sudden collapse of the Carboniferous Rainforest affected several large groups, including primitive tetrapods. Amniotes, being ecologically adapted to the drier conditions that followed, acquired new niches at a faster rate than before the collapse and dominated communities.Evolution and Diversity of Reptiles: A Summary

The Mesozoic era is commonly known as the "Age of Reptiles".
A 2021 study suggests that the diversity of reptiles in the Carboniferous and Permian was much higher than previously thought, leading to the proposal of a "First Age of Reptiles".
Reptiles are divided into four groups: anapsids, synapsids, diapsids, and sauropsids.
The ancestral amniote skull is uncertain, as some Parareptilia (traditionally referred to as "anapsids") have synapsid-like openings in their skull roofs.
Turtles are diapsids that evolved an anapsid skull structure to improve their armor.
Pelycosaurs were the first terrestrial megafauna in the Permian period, followed by therapsids.
The archosauromorphs and lepidosauromorphs evolved in the Permian and split into two main lineages: the forebears of turtles, crocodiles, and dinosaurs, and the predecessors of modern lizards and tuataras.
The archosaurs became the dominant group during the Triassic period, giving rise to dinosaurs and pterosaurs, while the mosasaurs were major sea reptiles during the Cretaceous period.
The Cretaceous-Paleogene extinction event marked the end of the Mesozoic era, with most archosaur and marine reptile lines becoming extinct.
Reptile diversification continued throughout the Cenozoic era, with squamates making up the majority of living reptiles.
Reptiles exhibit some form of cold-bloodedness, relying on external sources of heat to regulate their body temperature.
Reptilian muscle action produces heat, allowing for gigantothermy in large reptiles.
All reptiles breathe using lungs, with crocodilians having a muscular diaphragm that is analogous to the mammalian diaphragm.Breathing in turtles and tortoises varies among species, with some having a sheet of muscle that envelops the lungs while others use a series of special muscles to push their viscera up and down. Some turtles can breathe continuously during locomotion, while others hold their breath during terrestrial locomotion and breathe during rest periods. Reptiles produce sound mainly through hissing, but some species of crocodilians, lizards, and turtles have vocal cords. Snakes do not have outer or middle ears but have an inner ear structure that connects to their jawbone, allowing them to feel vibrations from sound waves in their environment. Reptilian skin is thin, covered in a horny epidermis, and has scales or scutes that provide protection. Reptiles continuously shed their skin throughout their lifetime. Excretion is performed mainly by two small kidneys, with uric acid being the main nitrogenous waste product in diapsids, and turtles excreting mainly urea. Digestion is slower in reptiles than in mammals due to their poikilotherm metabolism. Reptiles generally reproduce sexually and lay amniotic eggs covered with leathery or calcareous shells.Reptiles: Defense Mechanisms, Relations with Humans, and Captivity

Defense Mechanisms:

Avoidance is the most common defense mechanism in reptiles.
Camouflage is used to blend into their natural environment.
Some reptiles, like blue-tongued skinks and frill-necked lizards, use displays to ward off attackers.
Some non-venomous snakes play dead or exude a foul-smelling liquid to deter predators.
Some venomous snakes, like cobras and vipers, use venom to attack.
Crocodilians use their posture, hissing, and biting to defend themselves.

Relations with Humans:

Dinosaurs have been widely depicted in culture since their discovery.
The snake has played a powerful symbolic role in different cultures, often associated with death and rebirth.
The turtle is a prominent symbol of steadfastness and tranquility in religion, mythology, and folklore.
Snakebite can be treated with antivenom made from the venom of the snake.
Crocodiles and snakes are farmed for their hides, meat, and other products.

Captivity:

Reptiles are sometimes kept as pets, including snakes, lizards, turtles, and tortoises.
Herpetariums are zoological exhibition spaces for reptiles and amphibians.
Keeping reptiles as pets can be challenging due to their specific temperature and lighting requirements.