ExtinctZoo - The Scariest Dinosaur You've Never Heard Of

Episode Date: September 25, 2025

When it comes to dinosaurs, bigger always means scarier right? No, and not even close, as this one family of theropod has proved, who might just be just about the worst group of dinosaurs you could ever fathom getting snatched by.If this episode gives you a sense of dejavu, it's because this is a modernized, improved version of an older episode. Enjoy :)

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Co-Pilot handles the spreadsheets. Learn more at M365Copilot.com slash work. When Jurassic World was released, we got a look at the first hybrid dinosaur in this series, The Indominus Rex, which was a proprietary blend of a variety of animals and dinosaurs. Then, not so long after, we got our second hybrid in Fallen Kingdom, the Indo-Raptor, or as it's sometimes nicknamed, the Indominus Raptor. A horror movie-worthy creation that enjoyed the perks of a body much larger than what's seen in most real Dramanosaurs,

but still retaining a crazy level of agility, a sickle toe claw, and perhaps the hardest to miss, a set of slender man-like arms equipped with claws that would put Freddie Kruger to shame. And while it may be smaller than the Adominus Rex, this wombo combo of features certainly makes it a bit creepier, despite sharing many similarities. And it's no mystery why these two creatures share some aspects, as the Indoraptor itself was pretty much inspired by the question of what would happen if you combine the Adominus Rex with a real Velociraptor. But as it so turns out, we don't have to ask that question, because nature kind of answered it for us, just a really, really long time ago, about 150 million years ago, to be exact.

As it was then during the Mesozoic that a family of theropods emerged who were strikingly similar at appearance of the Indiraptor, but were in some ways even more bizarre and arguably more deadly. These were the Megaraptorants. Like the Indiraptor, this group is shrouded in secrecy and mystery, thanks to their minimal fossil record. And to date, researchers can't even agree on where they come from or what they are. but there is no argument that they would have made for the perfect Jurassic Park villains, as each one followed the same nightmarish body plan, which included this. What you're seeing here isn't a giant sickle claw on some supersized raptor's foot,

but a hand of all things, and it belonged to the Megaraptor, the holotype for the family and the first Megaraptoran to be discovered, being unearthed in Argentina before the turn of the century. And as its name suggests, paleontologists thought they had originally found a gigantic raptor, based on its massive claw which they believed to have belonged to a foot. However, we now know that this was a hand claw that sat on its first finger, and that it measured a whopping 30 centimeters or 12 inches,

making it about the same length as the longest bowie knives in existence, or just as long as your typical ruler. This also meant that the Megaraptor literally had the longest claws of any predatory animal ever, a title that would only be beaten by none other than one of its own, as over the next two decades, many new genera belonging to this family, were discovered, with a few being even scarier than their predecessor. And now the total number of Megaraptorans sits at 11 different genera. And crazily enough, these additional discoveries wound up teaching us that Megaraptorin's

iconic weapons were somehow much more lethal than first thought, as these theropods didn't just have one built-in sword, but two, as their second finger had their own enlarged recurved claws that were just like the first, i.e., shockingly sharp and very long. And what's crazy is that their claws were likely even longer in real life, as they were most likely covered in a keratinous sheath that might have added an additional 30% in length. And now, while the third finger did not have giant claws like the first and second, it was still razor sharp and powerful. But what made these claws truly deadly wasn't only their shape and size,

but also what backed them up, so to speak. As Megaraptorans had robust and proportionally large arms and hands that would have given theropods like the Tyrannosaurus Rex, some pretty major insecurities. These arms were roped in thick muscles, and the bones were constructed in a way that made them durable and highly flexible, allowing Megaraptorans to freely maneuver their weapons around with speed,

and letting them be used as either a sword or spear, depending on how they were feeling, which in both cases would lead to catastrophic flesh wounds and mass of internal damage. And even the death of the victim wouldn't have stopped the claw's onslaught, since researchers think that Megaraptorns likely use their claws to rake carcasses and tear bodies apart, allowing them to access hard-to-reach meat and disembowl their food.

Now at this point, I could stop here and still have it be plenty clear on why it would suck to be hunted by Megaraptorans. Yet this isn't the full picture. Oh no. As to truly understand the extent of their brutality, we have to talk about prey body size. You see, if a dinosaur was large enough, it's thought that Megaraptorans would have hunted it by using giant fatal claw strikes

and slashes to bring it down, before dicing their victim up into smaller edible pieces. This sounds bad enough, however, this is actually the lesser of two evils. As for smaller dinosaurs, including what would be human-sized ones, the megaraptorns did something much more unpleasant. They would first catch their prey, grip them, and pierce them like a shish kebab with their giant hooks, and then while they were still possibly alive, eat them. Kind of like a person eating a piece of pizza, only that the pizza is alive, has been impaled, and is definitely screaming.

We know this is a possibility, as Megaraptorans all had hyper-flexible and well-developed shoulders, there were unlike anything seen in most predators, implying a wide range of motion and the ability to lift things upwards towards their waiting mouths. And despite not being as deadly as their horrendous claws, their mouths were no joke either, and in some ways were actually more interesting.

Because unlike most predators, that have similar teeth to their relatives, the Megaraptorans had vastly different ones among them, each seeming to take inspiration from other notorious dinosaurs. For example, the Megaraptor had similar frontal teeth similar to those seen in pyranosaurids, being chisel-like and having a D-shaped cross-section. Meanwhile, the Moorris Raptor's front teeth were like fangs of all things. It got weirder though, as others, such as Australovinator and Orchiraptor, had teeth more like comsonathids and Dormeosaurs, with the front sides being,

smooth and flat, while the backs were serrated and designed to cut. And the mimicking continued with the Fukuiraptor, who might have had the least visually appealing teeth of them all, with its laterally compressed blade-like dentition, which highly resembled the Carcrodontosaurus, who, as you may know, is rather well known for possessing shark-like teeth. Now what's interesting is that studies have shown that Megaraptorans probably couldn't bite down or open their mouths with that much force. But given just how officially designed their teeth were, that wasn't really an issue,

to having a deadly bite, especially when you remember that the arms already had more than enough killing potential as it was. It's here in the teeth that the Megaraptorans also arguably get a win over the Indiraptor, because despite the Interruptor's teeth looking kind of scary, they were quite small and designed more for gripping rather than tearing or puncturing. And nature's own monstrosities take the prize in size as well, because of all the members we know of, the closest to the stature of the Indiraptor would have been the Eurosteon, an Argentinian genus who weighed one, 1.1 tons and measured 7.5 meters or 25 feet, nearly identical to the stats of Dr. Wu's creation. But the crazy thing is, is that this is actually considered to be on the medium size for this family,

not large, as they could get much bigger. In fact, nearly half of the Megaraptorans were larger than an Indiraptor, with the Orchoraptor, Megaraptor, and the Tratoyenia, all being over 8 meters in length. And at this size, some of them were the largest predators in their environment, and a few achieve some even more impressive feats. As currently, the largest Australian theropod is thought to have been a megarup torn, a fitting animal for a country, well known for their messed up wildlife. Still, it wasn't in Australia that you would find the largest member, far from it. As to meet a real giant, you'd have had to travel back to late Cretaceous Argentina,

where if you were seriously unlucky, you would have encountered the Maip. Yes, you heard that right, the Maip. But let me tell you, this somewhat funny-sounding name does not do. do it justice, as in reality, nothing about this giant theropod was comedic, especially for its prey. Not only was it the largest member in its family, but it was also a massive theropod in general, with recovered bones suggesting a length of up to 10 meters or 33 feet, longer than the length seen in the biggest conclusive allosaurus specimens. At this size, Maip was no doubt the biggest and baddest theropod in Argentina, and I likely preyed upon pretty much everything, including a variety

of ankylosors, hadrosaurs, and ornithopods. It might have even been able to hunt a co-existing titanosaur, the Nola Titan, by using its massive claws to tear and grip it while its mouth could then be used to deal additional damage. And while no claw belonging to this beast has been found yet, researchers estimate, based on its closest living relatives, that they were at least 37.5 centimeters or 15 inches long, giving it the title of the predator with the largest claws, even when including Freddie Kruger in the running.

And this is a notion that is adequately reflected by its name, which while may not sound intimidating in English, actually has a very sinister meaning, as it references a creature in Aounacank mythology known as the shadow of death that kills with cold wind. So yeah. Coming through a forest clearing and seeing one of these guys, or really any mega-rupt torrent for that matter, would have been a heart-thumping moment. But what might really stop your heart is seeing one start to run, because the moment it lifted its foot, you'd suddenly realize that they were much faster than they should have been. And there's a reason for that. Many dinosaurs have hollow or pneumatized bones, meaning they were filled with air pockets. But in Megaraptorans, this pneumatization was taken to an extreme level. So extreme, that only one of the theropod is known to rival their hollowness, and that's the Neovenator.

And what's interesting is that all of their bones possess this characteristic. but the ilium, vertebrae, and ribs were especially hollow, which together made Megaraptorans very light for their sizes. For example, the Megaraptor was only around one ton, while an allosaurus of similar length might have been 50% heavier. And it got even crazier than this, as some like the Australovinaator might have been no more than 310 kilos or 680 pounds, despite being over 6 meters or 20 feet in length,

which leads some paleontologists to think that certain genera were the cheetahs of their time. This surprising lightness helped turn this group into very agile and speedy killers, kind of like prehistoric ninja with giant chukos, and would have let even the larger ones chase down prey smaller than themselves, and stage stealthy ambushes. Not to mention, they also had leg bones that were relatively slender, and similar in construction to those seen in solarosaurs,

implying yet again more adaptations meant for running. And no surprise, such a design worked wonderfully to the misfortune of others. But unfortunately for them, this others could even include themselves, as fossil records have shown. Specifically, a muras raptor specimen, an Argentinian genus, was found with a severely infected brain case, which is thought to have originated from two different puncture marks on the side of its skull, that lo and behold matched the teeth found in its own mouth, meaning it came from arrival.

The extent of the infection was so severe that the team who studied the school believed that there is a greater than 50% chance that the individuals succumbed. to its injuries. But it is this aggressive attitude combined with its build that ultimately allowed the Megaraptorans to establish an expansive dominion, with species being known from three different continents, Australia, Asia, and South America, with Argentina, Australia, Thailand, and Japan, having been strongholds for members. In these countries, if you wanted to avoid running into one of these real-life Freddy Kruegers, you would have needed to steer clear from any sources of water, as Megaraptorans typically lived in wet environments, namely fluvial areas and coastlines,

where prey would have been abundant and diverse. There's even some speculation that some members may have opportunistically hunted marine and semi-aquatic animals, such as crocodilians, large turtles, and big fish. In fact, once upon a time, paleontologists actually thought that hunting in the water was really the Megaraptorans' main way of acquiring food, with the idea that they used their large claws to ensnare and spear fish. But nowadays, based on all their other adaptations, it's believed to be an unlikely story, and there is near-Universal Agreement that there were simply terrestrial hunters,

who were many times the sole apex predators in their environment. However, this wasn't always the case, and fossil records indicate that they had quite the rivalry with Carcrodontas swords, who were sometimes even bigger and specialized to tackle big game. This competition took place mainly in South America, and during it the Megaraptorans preferred to play into their agility, and speed, since it was only after the extinction of Carcrodontosaurus sorday, 90 million years ago, that they underwent a rapid size increase.

But funnily enough, despite their competition with the Carcadontas sorriday, they coincidentally shared a similar brain case shape and design, leading to some thinking that the two had comparable intelligence levels. Now, admittedly, carcrodontas soids are no Indiraptor when it comes to intelligence, but they have been compared to crocodiles, who despite misconceptions, can actually be quite smart. and are known to occasionally set traps, coordinate, and even once in a while, use tools to lure prey. So that's all to say, if any of this rubbed off on the Carcrodontasauridae and thereby Megaraptorans, neighboring herbivores would have been in for quite the nasty surprise.

Despite this shared similarity and the two's close but questionable relationship, Megaraptorans are currently believed not to be a part of the Carcrodontasauria, and actually no one really knows what these enigmatic killers were. Obviously they have their own family, but to which group of theropods they belong to is unknown. As their name suggests, originally paleontologists thought they were giant Dromasors, but this has since been discarded since they don't have enlarged toe claws. Then they thought that Megaraptorans are part of the Neoventoridae, given the similar hollowed bones, but that didn't last either.

And since then, two new schools of thought have emerged, with one side believing them to be tyrannosaurids, meaning their closest relatives were possibly Tyrannosaurids, or there were simply non-tiranosauroid, solurosaurs, which doesn't really tell us much either. And the mystery surrounding this group doesn't end with classification, as we also don't know where they come from. Currently, the best guess is that they originated in Asia,

possibly during the final days of the Jurassic. From there, they wound up in Australia some time in the early Cretaceous. After that, they ended up doing very well and became highly diversified, eventually carrying on their conquest to South America, likely arriving there via Antarctica. So quite the explorers, on top of being the perfect killing machines. And actually, they were so good at being hunters and simply existing that you could make the argument that Megaraptorn traits were more effective than what other theropods had. Because if you compare this group's survival time against others, it's basically a clean sweep.

For example, Tyrannosauridae achieved an existence of about 16 million years. Spinosauridae, 46 million, Carcrodontasauri, 64, Megalosauride, 25 million, and you get the idea. Meanwhile, the Megaraptorans clocked in existence spanning over 84 million years, making them among the longest-lived dinosaur groups, period. And opposed to some animals that tend to get smaller through time, it seems that they only got scarier and more overpowered, as the last iteration and surviving member happened to be the biggest and arguably the most deadly.

And of course, I'm talking about the Maip itself. And when you have a family as messed up as this, it really makes you wonder, how did they even go extinct? Well, it turns out that Mother Nature herself couldn't get the job done. Because like the non-avian dinosaurs as a whole, the Megaraptorans were only wiped out after a giant meteor slammed into the earth 66 million years ago, bringing an end to all non-avian dinosaurs and the last of the megaraptorans. And to this day, we're still waiting for a new animal to pop up,

that has claws even close to as impressive as theirs. Thanks for watching and until next time. Ambition comes in all shapes and sizes. At First Citizens Bank, we roll with your goals because we're built for what you're building. Fit for your ambition for Citizens Bank. On Extinct Zoo.