Reptile and Amphibian Comparisons

Reptiles and amphibians are grouped together by convention rather than by biology, and the pairing is itself a useful starting point. They are not close relatives: amphibians branched off long before the lineage that produced reptiles, birds and mammals, and the differences run right through the skin, the eggs, the life cycle and the physiology. Several pages on this shelf exist mainly to separate the two groups clearly.

Within reptiles, the most valuable comparisons are the crocodilian and squamate ones, because those are where casual identification most often goes wrong and where the stakes of getting it wrong are highest. This shelf treats those pages carefully. It describes documented structural differences — snout profile, tooth arrangement, scale patterns, pupil shape — as biology, while stating plainly that field identification of a live animal is not a safety procedure and must never be used as one.

Amphibian comparisons carry a different emphasis. Permeable skin makes amphibians unusually sensitive to their environment, which is why they feature so heavily in conservation monitoring, and it also explains why the frog-versus-toad and newt-versus-salamander distinctions are ecological stories about moisture and habitat rather than taxonomic ones.

What this section does and does not cover

Identification information here is educational. It is not a safety procedure, not a substitute for expert assessment, and never a basis for approaching, handling, capturing, relocating or provoking a wild animal. These pages give no first-aid, no bite or envenomation guidance, and no treatment advice. A suspected bite or sting is a medical emergency — contact emergency services or a poison control centre immediately.

Start here

Nested namesReptiles & Amphibians
Turtle vs Tortoise
A tortoise is a land-dwelling turtle in the family Testudinidae; turtle is the wider term for the whole order Testudines, most of which live in or near water.
Nested namesReptiles & Amphibians
Frog vs Toad
All toads are frogs; toad picks out drier-skinned, shorter-legged, more terrestrial anurans, with the name most strictly applied to the true toads of the family Bufonidae.
Close relativesReptiles & Amphibians
Crocodile vs Caiman
A caiman is an alligatorid restricted to the Americas with a hidden fourth lower tooth and bony belly armour; a crocodile is a crocodylid found across several continents with that tooth exposed when the jaws close.

How to read these comparisons

Never use an identification cue from this or any page to decide whether an animal is safe to approach — assume it is not.
Note whether a name refers to a species, a genus or a whole family, since several reptile names cover large groups.
Read amphibian pages with skin permeability in mind; it explains most of the habitat and behaviour differences that follow.
Check range before applying a cue, because several diagnostic differences only hold where the two animals actually co-occur.

All reptiles & amphibians comparisons

17 comparisons are filed here as their primary category.

Nested namesReptiles & Amphibians
Turtle vs Tortoise
A tortoise is a land-dwelling turtle in the family Testudinidae; turtle is the wider term for the whole order Testudines, most of which live in or near water.
Nested namesReptiles & Amphibians
Frog vs Toad
All toads are frogs; toad picks out drier-skinned, shorter-legged, more terrestrial anurans, with the name most strictly applied to the true toads of the family Bufonidae.
Close relativesReptiles & Amphibians
Crocodile vs Caiman
A caiman is an alligatorid restricted to the Americas with a hidden fourth lower tooth and bony belly armour; a crocodile is a crocodylid found across several continents with that tooth exposed when the jaws close.
Close relativesReptiles & Amphibians
Alligator vs Caiman
Alligators and caimans are the two subfamilies of Alligatoridae, separated by continent: alligators in North America and China, caimans in Central and South America.
Contrasting adaptationsReptiles & Amphibians
Gharial vs Crocodile
A gharial's snout is a narrow fish-catching instrument and it belongs to a separate family; a crocodile's broader snout handles a wide range of prey across several continents.
Contrasting adaptationsReptiles & Amphibians
Sea Turtle vs Tortoise
A sea turtle is built for open ocean with flippers and a fixed streamlined shell; a tortoise is built for dry land with clawed columnar legs and a domed shell it can withdraw into.
Close relativesReptiles & Amphibians
Green Sea Turtle vs Leatherback
The leatherback has a leathery ridged carapace and a jellyfish diet with exceptional diving ability; the green sea turtle has a hard scuted shell and grazes seagrass in shallow coastal water.
Look-alikesReptiles & Amphibians
Snake vs Legless Lizard
A legless lizard blinks, has ear openings and can shed its tail; a snake does none of these, because limblessness evolved separately in the two lineages.
Commonly confusedReptiles & Amphibians
Gecko vs Skink
Geckos have granular skin, mostly lidless eyes and often adhesive toe pads for climbing; skinks have smooth overlapping scales, movable eyelids and a low-slung ground-dwelling build.
Close relativesReptiles & Amphibians
Python vs Boa
Pythons lay eggs and are Old World; boas give birth to live young and are chiefly New World, and the two are separate families rather than variations on one.
Similar roleReptiles & Amphibians
Anaconda vs Reticulated Python
The reticulated python is the longest snake and the green anaconda the heaviest, and the difference in build reflects an aquatic ambusher against a terrestrial and arboreal one.
TaxonomyReptiles & Amphibians
Cobra vs Viper
Cobras are elapids with short fixed fangs and slender bodies; vipers are a separate family with long hinged fangs that fold away when not in use.
Close relativesReptiles & Amphibians
Coral Snake vs King Cobra
Both are elapids, but the coral snake is a small banded burrower relying on warning colouration, while the king cobra is the longest venomous snake, a snake specialist that builds a nest.
Nested namesReptiles & Amphibians
Newt vs Salamander
Newts are a subgroup of salamanders that are more aquatic and rougher-skinned; salamander is the umbrella term for the whole tailed amphibian order.
Close relativesReptiles & Amphibians
Axolotl vs Tiger Salamander
The axolotl retains its larval form and gills for life while reaching sexual maturity, whereas the tiger salamander metamorphoses into a terrestrial adult.
Contrasting adaptationsReptiles & Amphibians
Iguana vs Chameleon
A chameleon is a specialised arboreal hunter with independently moving eyes, a projectile tongue and grasping feet; an iguana is a larger, largely herbivorous lizard with conventional lizard anatomy.
Similar roleReptiles & Amphibians
Bullfrog vs Cane Toad
The bullfrog is an aquatic predator that eats and out-competes native species, while the cane toad is a terrestrial toad whose skin toxin poisons the predators that attack it.

Also relevant here

These comparisons are filed under another category but touch on reptiles & amphibians directly.

Chameleon vs Octopus

Elsewhere on FaunaHub

Alligator vs Crocodile
Snout profile, tooth arrangement and range — the three cues that actually separate them.

Related FaunaHub sections

Questions about this section

Can I use these pages to tell whether an animal is dangerous?

No. Please do not. Structural differences described here are documented biology, but applying them to a live animal in the field requires a clear, close, unhurried view that a real encounter rarely provides, and several rules that hold across most of a group have exceptions. Treat any unidentified reptile or amphibian as one to leave alone, keep your distance, and contact your local wildlife authority if an animal needs to be moved.

Are reptiles and amphibians closely related?

Not particularly. Amphibians split from the lineage leading to reptiles very early in tetrapod evolution, and modern reptiles are more closely related to birds than to any amphibian. The two are usually taught together for historical and practical reasons — overlapping habitats, similar survey methods, shared field-guide coverage — rather than because they form a natural group.

Why is venomous versus poisonous distinguished so carefully?

Because the two words describe different delivery routes and the distinction matters. Venom is actively introduced through a bite, sting or spine; a poison is harmful when it is eaten, absorbed or touched. Many amphibians are poisonous through skin secretions and are not venomous at all. Using the terms interchangeably makes descriptions of an animal's biology, and of the risk it actually presents, materially wrong.

How FaunaHub builds comparisons

How this comparison is built: FaunaHub comparisons are assembled from the sourced animal profiles behind them rather than written as standalone claims. Figures such as size, mass, and lifespan are typical ranges that vary by subspecies, population, region, sex, age, and — where relevant — whether an animal lives in the wild or under human care, so they are presented as ranges rather than fixed values. Where a common name covers a group rather than a single species, the page says so instead of implying a species-to-species match. Conservation status changes over time and should be confirmed against the current IUCN Red List. Dimensions that could not be supported from the underlying profiles are omitted rather than filled in.