50 Fun Facts About Reptiles and Amphibians

Reptiles and frogs live wild on six of the seven continents; which one has none of either?

Antarctica is the only continent where no reptiles or frogs live. On the other six they range from tropical forests to subarctic regions.

Which reptile, a hunter able to bring down deer and water buffalo, is the largest living lizard?

Komodo dragon males can reach 3 metres and 150 kg, making the species the largest living lizard. It survives on only a handful of Indonesian islands.

What name is given to the change that turns a gilled, swimming tadpole into an air-breathing frog?

Metamorphosis rebuilds a tadpole almost completely: legs sprout, a tongue forms and, a few days later, the tail is absorbed back into the body.

Which lizards can swivel each eye separately and fire a sticky tongue farther than their own body length?

Chameleons can watch two different objects at once, because each eye pivots and focuses on its own. Small species shoot their tongues more than twice their body length.

Old folk belief wrongly blames touching a toad for which skin growths, really caused by a human virus?

Warts come from the human papillomavirus, which toads do not carry. The myth probably grew from the bumpy glands on a toad's back, which look much the same.

Which living animals are the closest relatives of crocodilians, closer than any lizard or snake?

Birds and crocodilians are the only known survivors of the archosaurs, so a crocodile is a closer cousin to a sparrow than to any lizard.

A rattlesnake adds one new segment to the rattle on its tail each time it does what?

A rattlesnake sheds its skin several times a year and gains a segment each time, while old end segments break off. Counting the rattle therefore says nothing about its age.

In crocodilians and most turtles, which nest condition decides whether an egg hatches male or female?

Temperature during incubation sets the sex of crocodilians and most turtles. In many turtles a shift of only 1 to 2 degrees Celsius tips a nest from sons to daughters.

A snake flicking its forked tongue is collecting airborne particles to serve which of its senses?

Smell is what the tongue serves: its tips deliver particles to the Jacobson's organ in the mouth, and the fork tells a snake which direction a scent is coming from.

Which predator, ranging from India's east coast to northern Australia, is the largest living reptile?

Saltwater crocodile males typically grow 3.5 to 5 metres long and can top 1,000 kg, the most of any living reptile. Despite the name, the species also lives in freshwater rivers.

Which broad-snouted reptile lives wild in only two countries, the United States and China?

Alligator species survive only in the American southeast and China's Yangtze valley. With its mouth shut an alligator hides its lower teeth, while a crocodile shows both rows.

Which Asian snake, a hunter that mainly eats other snakes, is the longest venomous snake in the world?

King cobra adults average 3 to 4 metres, and the record stands at 5.85 metres. Despite the name it is not a true cobra and sits in a genus of its own.

Which lizards can run up windows and across ceilings on toes covered in tiny hairs called setae?

Geckos with these pads, about 60% of species, pack some 14,000 hair-like setae into every square millimetre, and the pads clean themselves of dirt within a few steps.

Which Pacific island group takes its name from an old Spanish word for the giant tortoises found there?

The Galápagos Islands were named by 16th-century Spanish explorers after galápago, their word for tortoise. The giant tortoises there can live for more than 100 years in the wild.

Which sea turtle, a deep-diving hunter of jellyfish, is the largest of all living turtles?

Leatherback turtles reach 2.7 metres and 500 kg and can dive to 1,200 metres. Alone among sea turtles they have no bony shell, only thick, flexible skin where the hard plates would be.

Which amphibian, shipped to Australia in 1935 to eat crop-destroying beetles, became a notorious pest?

The cane toad was brought in to protect sugar cane, then spread from its Queensland release sites to the Northern Territory border by 1984. Most attempts to halt it have failed.

Which vast United States wetland has been overrun by Burmese pythons descended from released pets?

The Everglades of southern Florida have held a breeding population of Burmese pythons since at least 2000. Marsh rabbits released there for a study were wiped out by the snakes within 11 months.

Which Mexican salamander keeps its feathery external gills for life and can regrow entire lost limbs?

The axolotl never grows out of its larval form and breeds while still fully aquatic. Its wild home, the lake system now largely covered by Mexico City, has almost vanished.

Which feature, visible on the sides of most lizards' heads, is completely missing in every snake?

Ear holes are absent in snakes, yet they are far from deaf: an inner ear linked to the jaw picks up vibrations as faint as soft speech in a quiet room.

Which New Zealand reptile looks like a lizard but is the last survivor of a separate, ancient order?

The tuatara is the only living member of an order that spread worldwide in the age of the dinosaurs. Its nearest living relatives are the lizards and snakes it resembles.

Which limbless, burrowing tropical amphibians are easily mistaken for earthworms or small snakes?

Caecilians have tiny eyes or none at all, and their name comes from the Latin for blind. The largest species grows to about 1.5 metres.

Which amphibian of Cameroon and Equatorial Guinea is the largest of all living frogs?

The goliath frog can top 3 kg, with a body more than 30 cm long before the legs are counted. Stretched out, the biggest specimens measure over 80 cm.

Which Southeast Asian snake, longer though lighter than the green anaconda, is the world's longest?

The reticulated python is a constrictor without venom, the world's longest snake yet only its third heaviest. A strong swimmer, it has been reported far out at sea.

Which flat-bodied desert reptiles of North America can squirt a stream of blood from their eyes?

Horned lizards can fire the blood up to 1.5 metres by raising pressure in the head until tiny vessels burst. It tastes foul to predators of the dog and cat families.

Which venomous lizard of the American Southwest has venom that led to a class of modern diabetes drugs?

The Gila monster makes exendin-4, the venom peptide behind exenatide and the wider GLP-1 family of drugs for diabetes and obesity. It is the only venomous lizard native to the United States.

Which Central American lizard, nicknamed the Jesus Christ lizard, can sprint across the surface of water?

The basilisk slaps the water with long-toed hind feet whose fringes of skin trap a pocket of air under each step. Once it slows it sinks, and swims the rest of the way.

Which Central and South American amphibians have see-through belly skin that reveals a beating heart?

Glass frogs are lime green from above, but their transparent undersides put the heart, liver and gut on show. Tucking in their see-through legs blurs their outline on a leaf.

Which North American amphibian, found even above the Arctic Circle, survives winter frozen solid?

The wood frog can survive with up to 70% of its body water turned to ice and no heartbeat at all. Its liver floods the body with glucose, which limits ice formation and protects the cells.

Which giant salamander of eastern US streams goes by folk names such as snot otter and lasagna lizard?

The hellbender is North America's largest salamander, at up to 74 cm. It rarely swims, instead gripping rocks with its toe pads and walking along the stream bed.

Which branch of zoology, named from the Greek for a creeping animal, studies reptiles and amphibians?

Herpetology treats the two groups together because Linnaeus once put reptiles and amphibians in the same class. Many amateur enthusiasts call themselves herpers.

What is the scientific term for animals, like lizards and frogs, that rely on their surroundings for warmth?

Ectotherms run on very economical metabolic rates, so a well-adapted one can go long periods without food. Scientists no longer use the older label, cold-blooded, as a technical term.

What term describes the cold-weather dormancy of reptiles, a different process from a mammal's hibernation?

Brumation takes its name from bruma, a Latin word for winter; a zoologist proposed it to set reptile dormancy apart from true hibernation. Rattlesnakes often pass it packed together in shared dens.

What name is given to the domed upper half of a turtle shell, joined by a bony bridge to the plastron?

The carapace is built from the turtle's own backbone and widened ribs, fused to plates of bone in the skin. A turtle can no more leave its shell than a person can leave their ribcage.

Which order, by far the largest among amphibians, contains every species of frog and toad?

Anura takes in about 88% of all living amphibian species. In classification terms every toad is a frog, though only one family counts as the true toads.

Which order, the largest among living reptiles, contains every lizard and snake?

Squamata, named from the Latin for scaly, share movable quadrate bones that let the upper jaw shift against the skull, which is how snakes gape wide enough for large prey.

What kind of organism is the chytrid pathogen that has wiped out frog populations on several continents?

A fungus is to blame: chytrids attack the skin that amphibians rely on, killing every animal in some populations. The disease spread around the world along trade routes.

Where do the eggs of the Surinam toad develop until they emerge months later as fully formed froglets?

In the mother's back, the eggs sink into honeycomb-like pockets of skin and stay for four to five months, until tiny finished froglets push their way out.

Which feared African snake is named for the colour of the inside of its mouth rather than its body?

The black mamba is usually grey to dark brown, and gapes to flash its inky mouth lining when threatened. Tales of its speed are exaggerated: it cannot top 20 km/h.

Which shy snake of remote central-eastern Australia is widely regarded as the most venomous in the world?

The inland taipan tops the tables for venom potency measured in laboratory mice, yet it is shy and placid and rarely meets people in its remote home.

Which tough protein, also the material of human hair and nails, makes up the scales of reptiles?

Keratin gives reptiles a horny, watertight skin, which is what frees them to live on dry land. Amphibian skin, by contrast, stays thin and moist.

The word amphibian comes from Ancient Greek with what meaning, apt for animals that start out in water?

Both kinds of life is the literal sense of the Greek amphibios, since most amphibians begin as gilled water-dwellers and end up as air-breathing adults on land.

Which organs are entirely missing in adult plethodontids, by far the largest family of salamanders?

Lungs are absent in all 500-plus plethodontid species, which take in oxygen through their skin and the lining of the mouth instead.

What is the term for a lizard's defence of deliberately casting off its own tail to escape a predator's grip?

Autotomy leaves the detached tail wriggling, which holds the predator's attention while its owner gets away. The regrown tail is usually shorter and stiffened with cartilage, not bone.

What is the single rear opening that reptiles and amphibians use for both waste and reproduction called?

The cloaca, also known as the vent, is the one exit for the digestive, urinary and reproductive tracts. Most placental mammals differ in having separate openings.

Which geological period, between the Devonian and the Permian, is nicknamed the Age of Amphibians?

The Carboniferous earned the nickname as early amphibians such as the temnospondyls became the dominant land vertebrates. Its swamp forests later turned into vast beds of coal.

What do biologists call bright warning colours that advertise a toxic frog or venomous snake?

Aposematism is honest advertising that an animal is not worth attacking. The zoologist Edward Poulton coined the word for Alfred Russel Wallace's idea of warning coloration.

Which fluid-filled membrane shields a reptile embryo, letting its egg develop on dry land?

The amnion and its fluid give the embryo a private pond inside the shell, protected from the outside world. Lacking one, most amphibians must still lay their eggs in water.

Which fossil 'fishapod', unearthed in Arctic Canada in 2004, shows fins turning into limbs?

Tiktaalik had scales and gills like a fish but a flat head and sturdy bones inside its fins, enough to prop itself up in shallow water about 375 million years ago.

What name is given to the bright orange, land-dwelling juvenile stage of North America's eastern newt?

An eft roams the forest floor for two or three years before it finds a pond and becomes an aquatic adult. Its vivid colour warns predators that its tissues are loaded with toxin.

Which geological era, spanning the Triassic, Jurassic and Cretaceous periods, is nicknamed the Age of Reptiles?

The Mesozoic owes the nickname to the 19th-century fossil hunter Gideon Mantell. It opened after the largest mass extinction in Earth's history and closed with the one that ended the dinosaurs.