Salamander Facts

Salamander Profile

Dinosaurs are the most popular prehistoric predators by far, but their time in the sun was surprisingly short and very recent, when compared to what came before them. After taking over from the Pseudosuchians, they reigned from the Late Triassic to the end of the Cretaceous. That’s roughly 160 million years. Not bad.

But amphibians dominated the swamps from over 360 million years ago, through the Carboniferous and Permian, and held their own through the Triassic, too. And long after the dinosaurs stepped down, Salamanders were producing Miocene monsters to hold the line.

Salamander Facts Overview

Salamanders today are a relatively recent offshoot of the primitive line of swamp guardians that branched off in the Jurassic. They were once part of a far larger group, but thicker skin would eventually come to take over the semiaquatic ecosystems they once reigned and their sensitivity to disturbance has relegated them to an ecological afterthought – though, a critical component of a healthy environment nonetheless.

Interesting Salamander Facts

1. Caudata

Salamanders might look like lizards, but they aren’t even lizard copycats, since their order has its roots way back in the grimy swamps of the Devonian, before even trees had come to dominate the land, let alone reptiles. Lizards, in contrast, might have originated as recently as the Triassic, over 100 million years later.

So, salamanders come from a true land before time, and a time before reptiles had been invented, and they’re perhaps more similar to their fishy ancestors than lizards are.

Back then, and for a long time after, Salamanders weren’t alone, and there was a whole group of relatives that made up the clade Caudata, which refers to their tails, and separates them from other amphibians that are closer to the frogs.

Today, though, there’s only one order of these amphibians left, Urodela, and this comprises the modern salamanders, which show up after lizards, sometime in the Jurassic.

And so, coming from such primitive roots, they have a lot of primitive features.  ¹

2. They heal

Salamanders are some of the most incredible of all vertebrates when it comes to healing. Not only can they regenerate their tails, like some lizards do, but they can also regenerate entire limbs, as well as organs like the heart and spinal tissues.

This is an ancestral trait to all animals that were once amphibians, which includes us. And so, geneticists are trying to find that specific switch in humans to see if it can be turned back on. While it would be very cool to regrow our tails, they claim that this is for the purposes of heart surgery and other serious operations, to prevent scarring. But that’s enough about us, let’s talk about salamanders.

3. They get huge

Salamanders are incredibly diverse in colour and size, and some in shape, too. The Axolotl is a weird little frilled salamander that’s perpetually in its juvenile state and so lives in the water all the time. The common newts from rural English ponds are also salamanders, albeit very little ones, but the largest, the Chinese giant salamanders, remind us of that Devonian swamp somewhat, where amphibians were the apex predators, and grew to worrying proportions.

The Chinese giant salamander is such an Amphibian of Unusual Size, reaching, as it does, over 1.8 metres long and a weight of over 50 kg.

And this is the largest on the planet today, but not remotely the largest that ever was. Salamanders don’t fossilise well, so we likely will never discover that record-holder, but the biggest we know of is Andrias matthewi, a recent Miocene arrival from the same order as today’s species.

This beast was over 2.3 metres long!

4. They get pretty

Salamanders really do come in all colours and patterns. Some are the standard amphibian green-brown, but others are spectacular, like the fire salamander, the “golden wonder” salamander, and many of the ambystoma genus, all of which come in bright colours and patterns.

The reticulated Flatwoods salamander, Ambystoma bishopi, is an almost snake-like example with stunning grey-blue tiger stripes. Fire salamanders come in splashes of deep reds and yellows, and the Golden Wonder is a gummy orange with a stark black contrasting stripe down its back.

It’s no wonder that salamanders are popular pets, but unfortunately, they are also some of the canaries in the coalmine of habitat destruction. ²

5. They get rare

We’re probably going to have a post on newts specifically, so it’s a good idea to move around a bit between other salamanders here, but before we do, it’s worth mentioning how many newts are also some of the rarest salamanders and rarest amphibians as a whole.

Gorgon’s cave newts have the best name for any amphibian, and are also a very weird animal, with a bulbous head and a dappled yellow/brown skin. It lives in a cave system in Iran, is almost fully aquatic, and that’s about all anyone knows about it.

It’s listed as Vulnerable on the IUCN, but also estimated to have a population of around 5,500 and is in decline. ³ 

But it gets worse. The Montseny brook newt is Critically Endangered, threatened by the drying out of its riverine waterways, caused by the arbitrary preference of people for bottled water from this particular region of Spain  ⁴

6. They get toxic

As amphibians, their skins are porous tissues, not like those of reptiles or mammals, and so salamanders are typically confined to humid areas, often even predominantly underwater, as is the case with most newts and the axolotl, which rarely and never come out, respectively.

This porous skin is both a handicap and a benefit, and one such benefit is that it can secrete dangerous defences in the form of toxins.

There are many toxins produced by various species of salamander, one of which is the infamous tetrodotoxin, or, if that’s not very familiar, the pufferfish toxin.

This is a wonderfully potent poison, and can quickly paralyse by opening all the sodium channels in the nerves so they can’t charge up to fire again. Rough-skinned newts are one such species that can make this. Figuring out how is still a fun mystery for biologists, but it looks to have something to do with the specific microbial ecosystems on the salamander’s skin. ⁵

7. They have enormous genomes

The human genome is around 3.2 billion base pairs long. It will be a disappointment to any Americans reading that this is not the largest genome in the animal kingdom, or anywhere close to it. But fortunately, that doesn’t mean much in terms of complexity.

Salamanders pretty much all have more than 10 billion base pairs in theirs, some up to 120 billion. This is kind of weird, and has all kinds of effects on the animal, including a very slow metabolism, and in some, like the axolotl, this is why they don’t go through metamorphosis at all.

But it’s also partially responsible for their ability to regenerate tissues, as their cells differentiate very slowly, and so they have a huge store of stem cells to put to use in healing.

So, salamanders are not only ancient but have an enticing genetic history, too, and potential as indicator species of ecosystem decline, purveyors of medical secrets, and scary toxins with which to hunt our enemies.

Salamander Fact-File Summary

Scientific Classification

1. (2022), “Skye salamander fossils are some of world’s oldest”, BBC.
2. Whitney (2024), “4 Best Beginner Pet Salamanders and Newts”,Pet Helpful.
3. (2021), “Persia Mountain Salamander”, IUCN.
4. (2021), “Montseny Brook Newt”, IUCN.
5. Gall et. al (2022), “Tetrodotoxin levels in lab-reared Rough-Skinned Newts (Taricha granulosa) after 3 years and comparison to wild-caught juveniles”, SicenceDirect.