ExtinctZoo - The Rarest Prehistoric Cave Discoveries

Episode Date: July 4, 2026

Caves kinda freak me out, so I am glad other people are brave enough to explore them leading to some pretty metal discoveries over the years.

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There are certain things in nature that just give you a visceral feeling, in the sense that some things might give you a sense of inherent danger, for example, or mystery. It's like if you stumbled into an ice ravine or a dense fong-trouted jungle, there'd probably be a little bit more emotions going on than if you were, say, just standing in a grass field. And of all the things you can find in nature, I think one that always hits a bit different are caves. I mean, you take one look at the mouth of a cave, and it instantly questions flood your mind. Like how far does it go? Where does the lead? What's in there? Are there monsters? Aliens? Is it dangerous? Are there giant drop-offs? Places to get stuck in and die horribly?

Etcetera, et cetera. Caves, for some reason, just tickle the hairs of nearly every human in one way or another. And this includes, by the way, paleontologists and researchers. And why you may ask? Well, just like how permafrost and tar pits are known for preserving some pretty crazy finds, so aren't caves. and they have played a monumental role in the field of science over the years. Now, just like anything in general, the discovery is made in caves very widely in craziness. And sometimes a cave will hold nothing, or a pretty common find, while other times was discovered is straight-up bonkers. And given that caves were for a large part of history essential to various group of hominens,

it's not a surprise that a lot of the finds actually relate to our kind, or at the very least, close relatives. And we've come to expect to find certain things in caves like cave-drawn, human artifacts, and even remains. Yet, I do think it's unfair to just glays primates only. And I want to instead shine more light on cave finds that are more inclusive, with a common denominator instead being that they are super rare and hard to believe. For example, there is a one-of-a-kind cave in Kentucky where palely told to stumble upon something that at first sounds almost impossible to have come from a cave. And that is sharks, lots and lots of them. Now hold your horses. I know you may

be thinking, um, extinct zoo, there are these things called underwater caves. And that is true, but this one is not, as it's the mammoth cave in the gobsmack middle of Kentucky, which for my non-Americans is landlocked and is about a 7.5 hour to 10-hour drive from any coastline. So it's a whole lot of land out here. And yet, within this cave, which fun fact also happens to be the longest cave system in the world, researchers made in odd discovery in 2019, which was that they found fossilized remains. of sharks. And not on the cave floor, mind you, but embedded into the cave walls and the ceilings themselves. In other words, a cave almost constructed by fossils. And it turns out that the sharks were a plenty, with hundreds of specimens being found. And up to this point, they've identified

over 70 species from this one place alone, including species of sharks like the clavisotins, which don't look anything like modern sharks. And the reason for this is that all these sharks are extinct, prehistoric, and extremely old, dating back some three-hospersedans, dating back some three 340 million years ago, all the way back to the Carboniferous period. And this is also the first clue as to why there were sharks in a cave in Kentucky. As that far back, the state was actually submerged in a warm, shallow sea now referred to as the Mississippi Sea, which was unsurprisingly absolutely shark-infested, and thus explaining their presence in the state. However, what's interesting is that the mammoth cave is not actually that old,

with a system only forming about 10 million years ago. And so it's rather that it's the bedrock itself that is ancient. Thus, while this means that sharks were unfortunately not frequenting a massive underwater cave system, as far as we know of, it does reflect an environment that was unusually chalkful of sharks. And even on top of the already described species, it was here that a researcher has also stumbled upon at least four new species of carboniferous sharks, not known previously. And a big reason why it's early sharks that dominate this cave and not other fish,

is that the carboniferous, despite being mainly known for insects, was in reality the golden age of sharks, as the group was experiencing extreme levels of diversity at the time. In fact, it was actually back then that they peaked, as since then, the number of shark families existing at any given point at time has been at a lower level, and thus hence, the golden age of sharks. And based in the cave's finding, it seems that this particular area was largely home to Catanicanta forms and Samora forms,

two separate but expansive groups of prehistoric sharks. That combined with the other lesser abundant groups, resulted in a water world where sharks were basically every kind of animal. And what I mean by this is that if you snorkeled in the spot back then, you would have seen some sharks nibbling on coral, others eating shells, and then of course those that were more traditional, so to speak, eating other fish. So in other words, it was sharks that were occupying pretty much every niche. And of course, since this cave is such an abundance of diversity,

it should come as no shock that the big dog in these waters has also been found in a cave. And that was the genus Sivodes, a large, great-to-white-sized shark that was equipped with seven big fins, two of which, by the way, had spikes on them, as well as hundreds of conical and cussed teeth in its jaws, which were designed to catch even the nimblest of prey, who were then often eaten whole. And though this was a shark-eat-shark-world, researchers have also ended up finding other animals in mammothothills, mammothed fish, eels, ray-like elasma branches, various kinds of coral and crinoids, brachio pods, orthocones, urchins, as well as conodonts.

Obviously, it's not every day you stumble into a cave in the Midwest and come face to face with fossilized sharks and marine animals. But we are just getting started. Because, if you think that would be trippy, just imagine this. One day you're in Chile on vacation and just exploring, when all of a sudden you find a massive and partially open cave in the Maggianas region. Being the intrigued adventurer you are, you enter. As you scour the walls and surroundings in the cave, you suddenly stumble and land into a pile of hardened balls and a mat full of skin and fur. Now, at first you may think you've landed on the shedding site of an animal, or perhaps someone just left their sitting rug behind, which would be odd. But no, the reality is stranger, which is that you were actually now sitting on the skin and fur of an ancient extinct giant, and it's a poop.

Now, this didn't actually happen to someone, per se, but it could have, because in 1895 it was in this Chilean cave, dubbed Cueve del Miladon, that explorers found a seemingly fresh piece of skin, along with fur, and a lot of other stuff, including what seemed to be dried dung. Pretty cool, if you're into that kind of stuff. But the real discovery came years later when these items were re-examined. And that's when we discovered that this material didn't belong to some random mammal, but a now extinct ground sloth, one of giant proportions. And that would be the myelodon. This chunk of an animal died out in the area some 10,000 years ago, and was among the largest animals still alive in the area at the time,

measuring up to 4 meters and weighing up to 2 tons. Now it was just one member of the giant ground sloths, a sadly extinct group now, but which not so long ago, was one of South America's most abundant megafaunal herbivores. While many members were browsers, using their tall stature to reach high up food, it's actually believed that the myelodon was more of a grazer that fed home exclusively on grass and sedges. Although, interestingly, one study in 2021 did find some evidence that if they chose to be,

myelodons could actually appreciate some umami flavor if you get my drift, being possibly omnivorous and consuming meat once in a while. Apparently, they also liked caves a lot, using them regularly as natural shelters, Thus explaining the dung, which indicated that at least one individual is here for a long period of time, well, then the skin might have actually been a sign that another died in this cave too. Whatever the case, just finding these things was extremely rare. And to find a full pelt that still looks fresh is absolutely bonkers, with a stable, cool climate of the cave having played a huge role in this excellent preservation.

It was also so well preserved that it's actually from this pelt that humans for the first time in history derived real DNA from an extinct ancient animal. with this particular myelodon being about 12 to 13,000 years old, making it roughly three times older than the very last mammoth. Unsurprisingly, the dung also held up pretty nicely, revealing the food it consumed and even the parasites that camped out in its guts, namely nematodes. Additionally, the remains were in such a condition

that we got a clear idea of what its skin texture and fur would have been like, with a team noting the skin to be incredibly thick and leathery, while then the fur was dense and coarse. So, in other words, pretty good protection, But obviously nature was like, that's not enough. Because then on top of that, they even discovered the presence of biological chain mail in the skin as well. Essentially, as thousands of small bony osteoderms were embedded into the dermis itself, giving this large tank some serious protection.

Along with these fresh findings, numerous bones were also excavated from the cave as well. And there were a lot of these, as collectively based on right to mandibles, it's been suggested that a minimum of 23 myelodons at some point used this cave. one of the largest aggregation of ground slot specimens anywhere in the world. So naming the cave Miladon Cave was a pretty fitting move. Although there were other animals found here too, mainly in skeletal form, as the bones of Macrikenia, archetherium, Smilodon, horses, and even some sort of giant jaguar, have all been excavated here.

Humans too actually utilized the natural shelter provided by the cave, with signs of sapient habitation showing up as early as 6,000 BC, so 8,000 years ago, with fire fractured rock, lithic tools, and even human remains having been found. And we've actually tested these remains, with the most recent test indicating that the human remains excavated belonged to a fairly elderly woman,

and thus partially highlighting how effective this cave in the surrounding area was, as supporting not just animals, but also groups of people. And fun fact, for a long time, the remains found here were considered the oldest evidence of human habitation in the entire region, which is just one more reason why

the Miladon Cave was such an anomaly of a discovery. But like I said in the beginning, humans or hominins in caves isn't anything new per se, and I pretty much can make an entire video on their discoveries alone. Though that said, I do have to show a little love to these discoveries, as some of it's been, well, seriously absurd. And one of the most crazy cave discoveries relating to our own kind

was made in the Siberian region of Russia. Where in a mountain cave in 2018, scientists came across a heap of human bone fragments, which included those of Neanderthals, modern humans, and then get this, something else. Amongst the collection was a seemingly insignificant pinky finger belonging to a juvenile female, which is nothing necessarily to write home about on its own.

But then two years later, scientists decided to extract DNA from several of the fossils, pink included, and what they found was a bit unexpected. As the DNA results showed this was not a sapient, Visit BetMDMGM Casino and check out the newest exclusive, the Price is Right Fortune Pick. BetMDMDM and Game Sense remind you to play responsibly,

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one that is now referred to as the Denysovans. We now know that this group of archaic humans lived across Asia from 200,000 to 32,000 years ago, and were capable of an extensive range of technology, with various stone tools being attributed to them. They're one of the few other homo species that we definitely, beyond doubt, interbreed with. With some modern culture, such as people from Papua New Guinea and the Aitca Magbukin in the Philippines, possessing between 3 to 9% Denysilvan DNA, which is not an insignificant amount by any means. As for comparison, most non-Africans only possessed up the 2% Neanderthal DNA. It was also here in this cave that the world's oldest needle was found as well, dating back to 60,000 years ago.

And in general, caves have been absolutely loaded with the oldest known types of man-made stuff. As across the board, it's from them that we have found the oldest known sewn clothing, oldest human burial, oldest mythical creature depiction, oldest leather shoes, and even the oldest signs of winery. So just emphasize again, caves have played a big part in our own. our history. Shout out cavemen. And if you want to learn about what's the craziest human discovery in a cave to date, in my opinion, then I would highly recommend you check out one of my older videos where I talk about the Noletti Rising Star Cave, a pretty wild case that also has to do with a new species and has some pretty bizarre mysteries surrounding it. And just as a little teaser, one thing

that's interesting with the Rising Star Cave is that a lot of the oddities seem to have been an intentional act, which you'll understand what I mean if you watch the video. Whereas then on the flip side, other cave discoveries have just been pure luck and good old mother nature doing her thing. And one very specific process that can occur in caves at random, but is also something we humans have replicated in specificity, is mummification. Yeah, just like the ancient Egyptian mummies you are familiar with, caves can do something similar, though it is very rare, as the condition of the caves in which the animal dies has to be just right,

being very stable, but in some ways also very extreme, like being hyperarid or super cold. And so understandably, such conditions are kind of like finding a needle in a haystack, or a needle in a cave. In other words, it happens very seldomly. But in the 2020s, one pretty massive discovery was found of this occurring at a level never seen before. This find was, perhaps unsurprisingly made in Saudi Arabia, within the brutally hot and dry Arabian desert. Where inside one unassuming cave, a team of excavators found the bodies of not one, two, or three animals, but seven, and larger ones at that. And that in alone is already kind of unusual, but what was really strange was the fact that these bodies were all exceptionally preserved and mummified, looking like they could have died a week ago.

And yet, the researchers knew this could not obviously be the case, as they were staring at an animal that did not exist in the region anymore. Cheetahs. In Saudi Arabia, the last wild cheetahs ever spotted were observed in 1973, and are for now considered locally extinct. Though to be honest, we aren't exactly sure why they went extinct in the region, or how, prevalent they were historically. And yet, here they were in this cave in 2020, mummified. And something curious about the mummies was that DNA testing found that all, but one of them, were not closer related to the last known Saudi Cheetahs, who were Asiatic, would these mummies instead appearing to be more close to the northwest African subspecies?

And this seems to be a result of the wide range in the age of the mummies, for these seven cheetahs did not die together, making their preservation all the stranger. And as a whole, they ranged from about 4,000 years old to just 127, with the youngest dated, being the sole one more related to Asiatic cheetahs. And what this indicates is that this cave was used extensively by different groups, it might have been a den for kittens. A hypothesis backed by the fact that on top of mummies, researchers would also find dozens of more cheetah specimens that were skeletalized.

Now, we're not sure why these seven in particular were mummified while the rest were not, but regardless, we should be counting our lucky stars. as despite being over 4,000 years old, the oldest mummy still managed to retain its physical shape, skin, teeth, and internal organs. And just for context, this makes it about 700 years older than the mummy of the famous pharaoh, King Tut. Pretty impressive, right? Now, with this said, there is another case of mummification in the cave that is touted by some as being even more rare, as it has to do with a species that is fully extinct,

and has really become the flagship of extinction to many. And that would be the Australian thylacine, also known as the Tasmanian tiger. This was the one-of-a-kind animal that memorably looked a whole lot like some sort of strange dog or wolf, but as a reality and unrelated marsupial that at one point in history ranged from Australia to New Guinea and obviously included the island of Tasmania. However, when Europeans first showed up on the continent, this predator was already extinct in New Guinea and mainland Australia. That said, it did leave evidence of its existence behind, be it through fossilized bones, indigenous artwork, trace footprints, etc., etc.

Though, of all the signs it left, that indicated it once lived in Australia, the starkest piece of evidence and the rarest, was located in Western Australia back in 1966, within, you guessed it, a cave. Specifically, the massive Null Arbor cave system. It was found in an L-shaped cave hole, now dubbed the thylacine hole, where researchers discovered a cesspit of animal remains, including a snake, lizard, bird, cat, dog, rabbit, kangaroo, wallaby, and Tasmanian devil remains. But then, deeper inside the hole, about 430 feet from the entrance, they discover something else on top of a rock pile. And that was a deceased

thylacine that had been completely mummified. The species was already considered extremely rare, or even extinct, worldwide at the time of the finding. So you can imagine their surprise when they found it, Not to mention the fact that it looked like it died relatively recently, as it was almost perfectly preserved. I mean, its skin and coat was distinguishable, with even the pattern of dark bars in its furs still being present, while then its tongue and left eyeball remained nearly fully intact. Even the tail was still there in one piece, albeit it had been attached at some point. But all in all a remarkable find, and shockingly the musk of decomposition still clung into the deceased animal. So imagine the shock to everyone when dating on the mummy found it not to be a few months old,

but rather a few thousand years old, between 4,000 and 5,000 years old, to be exact. And this mummy allowed scientists for the first time to compare the soft tissue of ancient thylacines with modern ones, which was a big deal. And to this day, it was this cave specimen that is regarded as the best preserved ancient Tasmanian tiger ever found. And there seems to be something going on with Australia's caves in general, as it's also in this continent that we've discovered was been dubbed the King of Cave Fines overall, the Narakort Caves. Located in southern Australia, this is actually a close-knit cluster of about 26 caves

that are all contained within 3 square kilometers, and is responsible for some of the most fossil-rich sediment on Earth. This place started collecting specimens, you could say, roughly 500,000 years ago, during the Middle Pleistocene. At the time, the area was a natural death trap for Australia's Ice Age animals, as the cave was really a pitfall, having a hole in the ceiling, and thus resulting in animals falling in, and then being unable to escape. and for hundreds of thousands of years at that.

And so, understandably, scores of organisms fell victim to the cave's traps, until literally the sheer amount of dead animals and seeping sediment formed a massive cone that eventually plugged the hole about 15,000 years ago, sealing this one-of-a-kind time capsule until it would be rediscovered once more by us in the 20th century when it was finally excavated, revealing the jackpot within. And what's so staggering about Narakort is the sheer amount of remains. As over 35 years, more than 5,000 specimens have been dug up, representing over 140 types of animals. And yet, crazily, it's thought that this is less than 5% of what remains are buried,

as there's approximately 5,000 tons of bone-rich sediment left, with some rough speculations suggesting that hundreds of thousands of animals remain in the cave. Another thing that makes the Narakort such an anomaly for its scale is that in many ways it's a snapshot at time, as unlike other sites where fossils remain but have been moved around by nature, those in Narakort are barely touched, with the animals still being in the same spot in position as they were when they died. So essentially, if you could somehow take a picture of Narakort with some especially powerful x-ray, you'd basically get a pretty grim and grotesque image of a bunch of Ice Age animals in extreme duress, a bit like how Pompeii preserved its victims

in their death poses. It's also known as a snapshot cave as entire ecological communities are preserved here, both predators and prey, small and large animals. There is a no discrimination. And from the little that has been unearthed, we've discovered giant kangaroos, thylacalyo, zygomoturus, multiple wombat relatives, wallabies, birds, bats, giant snakes like the Wanambi, rodents, bandicoots, and Tasmanian tigers. I mean, even humans, or rather a human, have been found in Narakort. But just not in the way you might think. As in the 1860s, a mummified aboriginal man, dubbed the petrified aboriginal, was found in one of these caves.

However, he was not a victim of the pitfall, like the other megafauna were. Instead, it's believed that he took shelter in the cave following an unknown injury, and ultimately died there before being mummified and calcified by a flow of stone directly above him, and thus giving him a petrified look. Unfortunately, we don't know much more about this man, as his remains were eventually stolen by his showman in the 1860s, and today his remains, or fate, is unknown. Still, mummified human or not, the Narakort is still one of a kind, and given his time capsule-like nature, it's often been used to study how ecological changes, climate shifts, and

extinctions have all impacted Australia's life. As if something determined it happened, it was ultimately reflected in what animals were falling into the pit. While then on top of that, the level of preservation of the specimens is also very unique, allowing us to study many extinct animals in great detail. And given the less than 5% of it has been explored, something tells me that Narakor's reputation will only continue to grow through the years. Thanks for watching, and until next time. on Extinct So.