ExtinctZoo - When Amphibians Were Earth's Main Source Of Nightmare Fuel

Episode Date: September 7, 2026

Kermit has a dark dark past....

Within the animal kingdom, there are some creatures that by name alone makes you instantly think danger. I mean, just imagine being stranded in nature and hearing that one of the following is chasing you. A bear, a shark, a big cat, a crock, etc., etc. Your palms have become sweaty, knees weak, and your arms heavy. Perhaps vomit on your sweater already. Mom spaghetti. No, but seriously, you'd automatically start panicking, even though all I said was bear, shark, whatever, not the specific species.

On the contrary, in the same situation, there are also certain animals that would cause no fear of it, such as being told a rabbit, beaver, hamster, or some amphibian was chasing you. Yet, the irony is that one of these animals they just named, while not being known as deadly today, was once upon a time, by far the worst thing you could run into. And likely based on the title, you'll know that I'm talking about amphibians. Yep, once upon a time, Kermit's ancestors were the deadliest things around. But what exactly is an amphibian? Now, obviously, I'm sure that you know frogs, toads, and salamanders are all amphibians,

yet few can actually fully define them. The old idea was that a creature who spends half its life in water and half on land fits the bill. But this is outdated. Instead, they're generally regarded as cold-blooded, four-limbed, and an amniotic vertebrates that make up their own basic animal group, the amphibia, with the other groups being mammals, reptiles, birds, fish, and invertebrates. Many amphibians share common traits, like a distinct life cycle and thin, porous, permeable skin. But like any group, there are exceptions to the rules. And today they are represented by

over 9,000 different species found across the entire world and on all continents, barring Antarctica. Surprisingly, or perhaps unsurprisingly, this makes them even more diverse than ourselves, mammals. Yet admittedly, they don't really reach where we do on the food chain. And whenever you think about apex predators, an amphibian isn't what you necessarily picture. But if you you dial the clock back, the story becomes a different one. Only thing is, this clock has to be in prime condition, because we've got to turn it way back, way, way, as in hundreds of millions of years, as the rule of amphibians began not just before the Ice Age, but even before the dinosaurs, with the beginning of this story starting during the Carboniferous, over 350

million years ago. Thanks to various media, this period has garnered quite a lot of attention in recent years, which honestly isn't so surprising, consider just how bizarre the Earth was during it. At the time, the supercontinent of Pangae had in yet formed, but its arrival was imminent, with increased tectonic activity bringing the land masses ever closer. What was truly unique about this period, though, wasn't something you would see on a map. You had to be on the ground to truly understand, as that is when you would notice that one kind of environment was seemingly everywhere.

Swamps. Today, swamps cover just 6% of the planet's surface, but back then, they counted for much more, let's say, which is essentially really. result of the right factors lining up at the same time, with much of the land being extremely low-lying, expansive, humid, and warm, or then sea levels at the start of the period were rising, leading to much of these lands being flooded by warm seas. While separately, rivers bringing water down from the surrounding mountains would also then flood these plains, essentially turning the lands into one giant soup bowl, and therefore priming it for the formation of vast, moist swamps, which are now

known as coal swamps, that covered large swathes of the equatorial regions. And if you track through any swamps today, you'll know they tend to be great for bugs, creepy crawlies, and then, of course, amphibians, who benefit from the abundance of safe places they create, food provided, and moistness, which keeps their eggs and skin nicely hydrated, no wrinkles for them. And so, with so much of the Earth being peak real estate for the group, amphibians, who had only evolved the period prior, they rapidly started to take over the planet, expanding across the continents and evolving at a blindingly fast rate, resulting in an informal era, now known as the age of amphibians, among other things.

Now, it really didn't take long until amphibians were basically everywhere. Yet, more importantly, not very long if there were also basically everything. In the sense that they filled a wide range of ecological niches, meaning your neighborhood-friendly herbivore, amphibian, a small critters scampering around, amphibians too, and then the metaphorical big bad wolves, were also, as you can probably guess, amphibians. And in this department, they really didn't hold back. with just about every puddle, swampy thicket, river, and mud hole,

being home to some nightmarish amphibian. I mean, it was so bad, even on land, which, you know, the whole amphibian thing, you couldn't get away from amphibians. And a certain pioneer in this area of terrifying creatures was a group known as the Temnosbondles, the now extinct order primitive amphibians that found great success in the swampy oasis,

developing into a plethora of different clades and families, all with their very own scary quirks. Although, that said, one group of Temna spondals that stuck out like a sore thumb, being just about the worst thing you can encounter, were the Edo poedia, a family that might have evolved earlier into the Carboniferous, but really started to ram things up towards the end,

with numerous apex predators stemming from them alone. On the surface, these absolute units looked like some sort of experiment where a salamander was crossed with a crocodile, and then it all went wrong. With most of them possessing relatively giant and broad heads, wide bodies, and bumpy, lumpy skin created by deep grooves in their bones. A trait actually seen in all temnospondals, which might have been to help reinforce their bones, keep them cool, and house a dense network of blood vessels.

Separately, many edipoids possessed robust and stout legs, which probably weren't designed for swimming. As interestingly, unlike other amphibians, most of these guys lacked lateral line canals, which is a special mucus-filled tube beneath the skin. That usually lets aquatic amphibians detect water currents, pressure changes, etc. And because a lot of edipoids didn't have any, some paleontologists believe that the majority of these units were adapted to primarily terrestrial lives, though they probably still had aquatic

and semi-aquatic habits, centered mainly around their life cycle and breeding seasons. Yet ultimately, it was land where you truly had to fear them, with the belief being that many edipoids were deadly ambushed hunters, using the dense swamps to camouflage their hunkering bodies while they laid in wait until an unsuspecting animal came just close enough, where they would then lash out in blinding speed and nab the unwary creature, with their proportionally giant jaws, often lined with gripping teeth and fangs. Yes, literal fangs that deeply punctured through flesh with immense force, which was then further backed by faces that tended to be unusually thickened, supplying them with some extra chomping power, leaving very little

room for any caught animals to slip out from their demise, no pun intended. And given how big some of these guys were, with search in general like the E-DOPs, being as long as three meters or nearly ten feet, and weighing some 200 kilos or 440 pounds, it's also been suspected that smaller prey might have just been swallowed whole. And seeing just how wide this thing was, with it pretty much having been a bull shark-sized salamander, but with an even bigger head, I personally wouldn't want to test out the hypothesis that humans could potentially fit as well. And for any time travelers out there, going out for their remains and tracks, these stealthy killers largely lived in the subtropical and tropical environments of LaRussia, and therefore making all hikes there, quite ill-advised. And really, it's not just large carnivorous salamander crocs that makes walking here a questionable excursion,

as Edipoids weren't the only land amphibians to watch out for, for there were other, even otter groups, such as what I like to call the murder pugs, also borrally known as scientifically the disarrophadee. And I think it's pretty clear why I nicknamed this when you see them, as visually they looked just like a pug. They had compacted out bodies, short tails, similar sprawling legs, and were in many cases, even pug or almost pug size. while a few were smaller and then others larger, such as the platystrix, a one meter or 3.3 foot long genera that was likely heavier than a pug too, given that a uniquely possessed a sail on its back as well, like a dimetrodon, which may have also been used for thermoregulation or species identification. Other disherophody were also likely heavier than meets the eye. As even without a sail, nearly all of them happened to be armored, possessing heavy and wide bony plates, known as dermal osteoderms that ran down their backs in a linking fashion, helping to protect the, them against other predators and likely stiffening their spine a bit to help them move around on land.

As these guys, despite being amphibians, were apparently fully terrestrial, living and hunting entirely above water. India, I said hunting, as these were murder pugs after all, who were equipped the razor-sharp marginal teeth, and then thousands of needle-like denticles that cover the roof of the mouth, that helped them hook prey when biting down. Kind of like those metal dog brushes, but instead of pulling out dog hairs, it's digging into skin. Oh, and before I forget, it turns out that many Temptosophers, spondals, including the larger ones, had these hook-like denticles as well, which widely varied in size. And so armed with these teeth, these Decerophate, despite not being necessarily giants, were able to prey on a diverse range of animals, going from large bugs and smaller arthropods to other amphibians as well.

And sure, while one of these guys wouldn't be deadly to an adult human, I'd still sure as heck not want to find out what his needle-filled mouth felt like. And you might think that with all these predators to go around, the earth couldn't fit anymore. But really, that couldn't be farther from the truth, especially as you winched closer towards the swamp's water. As after all, we are talking about amphibians here. And it was really inside and around the waterways of Carboniferous Earth, where you'd find the densest concentration of them, with some fossil assemblages being so rich in amphibians that if you stuck your hand in the waters and pulled the first thing you felt, chances are it wasn't going to be a fish or even arthropod.

It was likely going to be an amphibian and a temnospondal at that, as they held the power here as well, with a plethora of varying kinds calling the waters and their banks home. Just like elsewhere, there was a long list of different kinds of aquatic carnivorous amphibians. But the worst of the bunch were arguably the Ariopidae, a family of amphibians from North America and Europe that were almost always the apex predators of their environments. In some cases reaching sizes that even rivaled that of the Edipoids. Take the Ariop's, for example.

A monstrous hunk of a predator that also grew to around 3 meters, were nearly 10 feet long, and was just as heavy, maybe even slightly heavier than the E-DOPs, thanks to its extremely robust build, making it one of the biggest swamp puppies out there. And though it was one of the last Eriopidae to evolve, many of the earlier kinds were still megafaunal carnivores that inhabited lowland areas, including in and around, ponds, streams, and rivers, using their muscular tails to help maneuver. However, that said, based on what researchers have gathered, the Eriopidae you'd find in certain areas would actually mostly depend on their age, in the sense that juveniles

seem to prefer staying in the water exclusively, where the outrageous amount of drowned plants and trees provided ample hiding spots, while as adults these guys would become more common along the banks of water sources, letting everything know who the true bosses were around these parts. Interestingly, and mirroring many modern amphibians, this which in preferences, let's say, as they aged, might have been the result of changes in swimming capability as they matured. with many kinds, including the Aereops, being surprisingly poor swimmers due to their hefty, often rigid bodies, that made swimming gracefully pretty much a pipe dream. Yet, in spite of largely chilling on the shores, fish and aquatic tetrapods still consisted of a large part of their diet,

which we know going after a skull and jaw anatomy, which indicates a specialized hunting strategy of gripping slippery prey and chucking them whole down the gullet, instead of chewing and slicing meat, hinting that despite their impressive sizes, they were in fact limited in how big of an animal they could. hunt. Although, seeing just how big they were compared to everything else, I doubt that factor usually limited them. And ultimately, they, along with other Temnosbondles, did exceptionally well for themselves during this age of amphibians, which kind of makes sense considering the name. In fact, being an amphibian was so advantageous that even things that weren't them were trying to get in on the action. In the sense that, just like how we have carnacization now,

with everything turning into a crab, back then it was amphibians that were all the rage. And the best example of this was the ambolomery. Now, to be honest, it's actually unsure what this highly successful group of animals were specifically, as originally they were thought to be amphibians, yet this idea has shifted, and now we aren't too sure where they belong, with different hypotheses on the matter. But it does seem that everyone agrees in one thing, which is that these guys are only honorary amphibians, meaning they're definitely not true ones. But they sure did earn that honor a title, as while yes, I'm no amphibian expert, they surely could have fooled me, looking essentially superficially like any other amphibian, while also possessing eolike bodies,

somewhat resembling that of the extent amphiumidae, and then also having large, latally compressed tails, and even having slimmer reproduction practices and lifestyles to many temnospondals. And as a result, it was the ambulomery, besides fish, that were mainly sharing the swamps of the amphibians, becoming specialized to me aquatic predators of their own, that could even rival the temno spondents, in prowess and power, producing multiple megafaunal genera, a few of which, by the way, were even longer than any known temnospondles from this time, such as the Faladurpeton, a 4 meter or 13 foot long embalamary from late Carboniferous England that preyed upon bolt fish and other tetrapods that wandered too close to the water's edge.

Now they, like other emblemaries, were distinguished by a naut type of tooth known as labyrinthodon teeth, which featured complex maze-like folding enameles and dentine, essentially creating trippy dental patterns, which served. to give their chomper's additional reinforcement when attacking prey or competitors. These teeth also tended to be exceptionally sharp and conical, well then accompanied by recurved side teeth and enlarged palatal tusks designed to stab deep. And just to complete the package, the ambolomaries also had a well-developed sense of smell, which was the poignant tool in the murky swamps,

as visibility tended to be not the best, which was just one more feature that allowed them to become just as widespread and arguably successful as the temnos spondols. And together, these two, These two groups made sure the swamps of Carboniferous had its fair share of nopeness. Yet, just like Shrek's swamp, the Carboniferous was about to get a rude awakening. This towards the end of the period, a large shift in the Earth's climate and atmosphere occurred, leading to the planet becoming cooler and drier, while sea levels drastically dropped,

and poor-timed volcanism began, which, as you can probably understand, were all quite unfavorable for the coal swamps, causing them to dry out and be replaced by drier biomes, while the infrequent forest fires also ravaged them as well, ultimately reducing their extent and turning them into fragmented environments, whereas before they were largely connected. This event, now known as the rainforests carboniferous collapse, was a relatively minor extinction, but effectively ended the swampy phase of Earth's history,

and it was a major paradigm shift for the landscape, causing lots of final turnover. But that being said, the ruling amphibians weren't ready to stop the train just yet. As contrary to popular opinion, the group actually remained exceedingly diverse going into the preceding Permian, especially the early Permian, residing in the coal swamp refugia that lingered on, and pretty much any other place moist enough, with a high concentration of them being found on the paleo continent of Cathasia.

And in these refuges, amphibians didn't only continue to survive, but they also continued to evolve, diversifying into new species and groups, leading to the early Permian often be included in the age of amphibians. And somehow, some of these new faces were either just as ugly or even uglier than the previous ones. Take the archa gisorodia, for example, a super family of temnospondals who had a very impressive range, and were some of the most dominant creatures in freshwater and brackish environments throughout the Permian, being largely aquatic animals who were actually more metabolically and physiologically akin to fish than to modern-day amphibians, despite being, well, again, amphibians. But then, from a visual standpoint, a lot of them resembled crocs more than either fish or amphibians.

I mean, just take a look at this thing. It essentially looks like a crocodile that forgot its own. armor at home, or maybe like a Timu crocodile or something. And just like crocodiles, some of these fearsome predators got pretty big too. As to a genera like the Melasaurus, which hailed from Permian Russia, and grew up to three meters or 9.7 feet in length, consuming prey such as fish and tetrapods like the discosaurus, which was verified by actual fossil remains. And just like how nowadays there's a saying that there's always a bigger fish, well, that tended to be true here as well. Only replaced fish with amphibian. It's another massive archicosaurus. It's another massive

archicosaurid was the prionysuchus, which was somehow even bigger and potentially the scariest amphibian to spawn from the age of amphibians. Residing in what is today northeast Brazil during the early to mid parts of this period, the prionysukas was a long-snouted, absolutely gigantic tenospondal that can make even the larger carboniferous amphibians look kind of like tadpoles. And I say it could, because for a long time, all specimens attributed to this genus were big, but not necessarily supersized, hovering around the same size as a person. But, But then one year, researchers stumbled upon a fragmentary specimen that was basically like the Arnold of its generation, being three times the size of other specimens, reaching a length

greater than 5.5 meters or 18 feet, meaning that we had amphibians as long as freaking giraffes are tall. And this made the Priynausus among the largest amphibians to ever exist, while then also surely being the biggest of its time, and an undisputed apex predator within its environment. On the surface, this thing heavily resembled some sort of primitive gharial and possibly lived a similar lifestyle, using aquatic ambushes to feed upon fish, as well as other slippery animals. With its unusual size having let it pick on just about anything it wanted to, almost anything, that is, with some of its relatives probably being just a tad bit too big for it to tackle. There were other temnosbondles as well that were in the safety zone from a size perspective as well, including some of the giants from the Carboniferous that had survived the rainforest collapse. like our old friends, the ARIOPs and Edobs, amongst others.

On top of this, the murder pugs were still running about as well, and you can't forget the Diploccaladee either, a relatively well-known family of amphibians, distinguished by their strange kite-shaped heads. That might have been some sort of biological hydrofoil, allowing them to control how water passed over them while swimming, letting it rapidly adjust its depth at any moment. Now, yes, overall, these guys were essentially critters

compared to some of the larger temnospondles, but at the end of the day, they too, were successful predators, predators who might show you a thing or two if you wagged your fingers too close to their mouth, if you get my drift. And really, just like a roller coaster, it'd be best to keep all hands and feet inside the time machine during the Permian, seeing that there were still numerous groups out and about that I haven't mentioned yet, who were absolutely killers like the rest, even if they weren't as dominant or giant, including the Rhinususory, Dhinosaurs, cochleosauridae, trematopidae, and the Xatriciaeidae, who were an odd bunch of amphibians that may have used special glands

designed to produce a thick, sticky substance to hunt, licking prey and literally trapping them to their tongues like a fly trap. And somehow, there are even more amphibians out there than this, which we know exist despite having never been found, as sometimes the only thing left behind by animals isn't fossilized skeletons, but rather trackways. And in some cases, such as those found in South Africa, these trackways can be quite large,

representing unknown genre of amphibious predators that were around the size of a crocodile. So evidently, amphibians were doing just fine, following the end of the Carboniferous. Yet, their strong start to the Permian wouldn't convert to the later stages, as Mother Nature had plans for the planet, with the climate following a trend of just getting hotter and drier for the most part, with a now-formed Pangaea, slowly being taken over by seemingly endless amounts of deserts, while the little coal swamps that remained kept shrinking and shrinking. And when the Permian finally came to a close, everything only got worse, thanks to the Great Dying.

Which is, if you haven't heard me say this by now, the worst extinction to ever hit Earth, resulting from massive volcanism that transformed the entire world into essentially a hellscape. Heat, flames, smoke, you name it, it happened. And do you want to guess if the Temnospondals, a group that would absolutely hate these things, died out with the over 90% of the other life that went extinct? Well, the answer is sadly, yes. Yes, they lived, that is, as against all odds, amphibians and Temno Spondles somehow survived this this travesty, and not only that, but they were able to make a massive comeback, which for a long time was a literal mystery to paleontologists, but is now partially believed to be due to their

capability of hiding in the sparse bodies of water that remained, being able to go long durations without food and successfully preying on freshwater fish that were inaccessible to terrestrial predators. Whatever the case, though, it was the amphibians who were arguably one of the few benefactors of the Great Dying, quickly repopulating the tracic waterways and establishing themselves for one last time as the true river monsters of Earth. Some of the groups I mentioned consisted of this last hurrah, but, again, like last time, there were new faces as well, one of the more prominent being the Capitasores, a group of relatively large amphibians that held a wide range across Pangaea,

living within rivers and lakes. They seem to have filled niches similar to modern crocodiles, relying on ambushes and having a powerful set of broad jaws, featuring piercing massive tusks and fangs, which just seems to be a trend amongst hemispondles. Numerous genera of capytosaurus were larger hunters, but the biggest by a clear margin was easily the mastodonsaurus, a middle triassic member from Europe that was an apex predator in both freshwater

and even potentially marine ecosystems. Thanks to its huge jaws, a powerful tale, and not to mention giant size, with this thing being a true behemoth, as it was one of the largest amphibians ever, and breaking the prionisucas's previous record, with adults being able to measure up to 6 meters or 20 feet long, while then also weighing up to 2 freaking tons. And isolated teeth fragments suggest they could get bigger than even this.

So to put that into perspective, we are essentially talking about killer salamanders that somewhat resemble crocs, but are the size of rhinos, who fed on not only just about every fish around them, but also the newly evolved archosaurs that dared to risk a drink. And considering these lands were so brutally hot, hunting animals would have been like stealing candy from a baby. What's crazy is that somehow not even this group would produce the largest amphibians of the Triassic,

as another new family in town were producing titans of their very own, and this would be the brachio poitia. Surprisingly, or perhaps unsurprisingly, considering the present-day state of this place, these guys first evolved in Australia during the later Triassic. And while they are not closer related to living salamanders, you can't deny that they kind of look like their long-lost twins, with their body shapes being quite uncanny in similarity. Well then their heads were also relatively large for their bodies,

in fact, being proportionally much bigger than even a giant salamander's head, which was possibly designed to let them rapidly open their mouths and draw in large amounts of water, along with any animal in said water. And while a good chunk of this group eventually became rather large genera, there has been one specimen in particular stemming from an undescribed brachyopoid that wasn't just big for this family, but pushes the envelope on how big amphibians can get, period.

As within the country of Lesotho, a paleontologist found a jaw fragment belonging to a late traasic amphibian, now dubbed the beauty of the situ, which might have grown to be 23 feet or 7 meters long, which is, for perspective, longer than the longest Great White ever recorded, and making it one of the largest trassic animals known to date, when you exclude the oceans of Earth. Now, a brachyopoid of this size was, without question,

a top predator within its watery home. And would have probably lived someone like an oversized crock, snapping up animals left and right, using ambush tactics and quick bursts to speed. So, if you went back in time and saw this thing hunt, it might be eerily similar to watching a documentary show a crocodile snatch a wildebeest right from the water's edge. Only this time it's happening on a bigger scale.

And what's being yoint into the water is another wacky triassic animal. Now, if the estimates for the beauty of Lesotho remain true, as there is some speculation, it would mean that it was during the Triassic, not the carboniferous, when amphibians reached their climax in size. And it wouldn't be the only achievement hit during the early Mesozoic, as it was then that the world also saw the arrival of the only known superfamily of amphibians that might have been fully adapted to marine environments. And this was the Traumatooroidia. The closest thing we've gotten to have jaws had been an amphibian. Emerging during the early Triassic, this group of medium to large-sized amphibians was able to achieve a very extensive global range.

to, as you probably can guess it, their ability to traverse large open waters. A remarkable achievement for any amphibian is usually salt water is essentially a lethal bath for them due to their highly permeable skin. And with this, oh so unique power, it wasn't uncommon for single genera such as the aphanarama, a bluefin tuna sized member, to be found across the planet in lagoons and shallow seas. Like many others of its kind, this genus boarded a highly long and narrow snout, slimmer to agarials, indicating a predominantly paciferous lifestyle.

However, there were variations, as some traumatosaurs ended up evolving broader jaws, as well as operating in different niches and having their own hunting strategies, with some probably being a bit more generalistic. But one thing they united them all were their exceptionally powerful and muscular tails, along with their hydrodynamic bodies, which transformed them into exceedingly efficient swimmers. Although, interestingly, unlike other animals that have returned to the waters, they retain their hands instead of evolving flippers, meaning it is plausible that they could have wander into very shallow waters or even briefly going into the shore. In other words,

not even someone chilling on the beach was out of reach of marine amphibians. So, as you can see, there was essentially no escaping amphibians no matter where you went for a surprisingly good chunk of Earth's history. However, as I say that, if you look around now, you'll notice that something has changed and that something began at the end of the Triassic period with the Triassic Jurassic event, one of the Big Five. And similar to other extinctions, this two is believed have resulted from massive volcanic eruptions. But unfortunately this time, amphibians would not be spared. In troves of temnospondles were eradicated from the planet. Now, they would ultimately survive, and you could even still find some pretty nasty ones hiding out, mainly different types

of brachyopoids, yet this was the beginning of the end. And through the Jurassic and early Cretaceous, temnospondals would keep declining until they finally disappeared. However, in their place, a new kind of amphibian would actually rise, to list amphibia. And to see what these guys look like, I'd say just go visit your local watering hole. I made some videos that include them. Thanks for watching and until next time on Extinct Zoo.