Extinct Creatures That Would Wreck The Earth If They Were Alive Today

The rise of human beings from wussy tree-dwelling primate to conquerors of planet Earth was largely due to luck. We evolved during a time when most truly horrifying predators existed only as fossils, which means we could do things like walk around on the ground, swim in the ocean, and live past the age of 19.

Which does sort of make you wonder, what would become of the human race and the modern world we live in if suddenly some higher power just resurrected all of pre-history's most terrifying creatures? Would we still have beach vacations? Camping trips? Ranching? Survival in general?

Thankfully, the era of enormous, terrifying predators is mostly over, with the exception of grizzly bears, crocodiles, and the Discovery Channel. But because it's fun to look back through time and ask ourselves "What if?" let's have a look at some of those horrifying, real-life creatures of bygone eras that would almost certainly wreck the modern world if they somehow managed to make it to the 21st century.

The F-104 Starfighter has a wingspan of just under 22 feet. So did the Argentavis magnificens, but one of those things is not like the other. The F-104 Starfighter is an airplane, and the Argentavis magnificens was a bird. That's right, a bird that was literally the size of a freaking airplane. So if this creature existed today you would probably just not want to go outside, ever.

According to Ameghiniana, Argentavis magnificens lived in Argentina roughly 6 million years ago. It was a vulture, but it didn't eat just carrion. Scientists think it also consumed prey, like large rodents, small armadillos, and camels. Yes, camels. Granted, the camels of 6 million years ago were only the size of large deer, and Argentavis were probably only feeding on young camels but still, daaang. If this thing were alive today it would seriously change the goat farming industry, that's for sure.

But Argentavis magnificens was not actually the largest bird that ever lived (that we know of). That honor belongs to Pelagornis sandersi, which had a whopping 24-foot wingspan. Scientists think Pelagornis sandersi probably preyed on things like fish and squid, so it probably wouldn't go for a person but still, imagine what it would be like to get crapped on by one of those things while you were whale-watching. It might not wreck the world or anything, but it would sure wreck your day.

Who doesn't love snakes? They're so cuddly and huggable and venomous and too small to constrict you to death and actually eat you or anything, with a few horrifying exceptions. The largest snake alive today is the giant anaconda, which grows to about 17 feet and can weigh around 550 pounds. (Some anacondas have been noted at around 30 feet in length, but let's just bury that little tidbit as deep as it will go, hmm?)

As horrifying as the idea of a 550-pound snake is, it's only about 22 percent as horrifying as a 2,500-pound snake. Now, at 42 feet, titanoboa was only marginally longer than the longest living anaconda, but it was nearly a ton heavier which means it was more like a horrifying, horrifying, horrifying worm than a snake, except for the whole constricting you until you die thing that worms don't tend to do. According to Smithsonian, if you stood next to one of these things it would come up to your waist, at least temporarily because then it would be eating you and you'd no longer be, you know, standing.

So let's imagine what life would be like if this creature were roaming the suburbs. We wouldn't have cats anymore, or dogs, or horses ... or probably circus elephants either. On the flip side, we wouldn't have to worry about bears in our campsites because the titanoboa would eat all the bears.

So imagine if a T. rex had a baby with a chicken and then an ostrich had a baby with one of those ginormous Steller's sea eagles and then the two babies grew up and met each other on Tinder and then their offspring decided to turn the entire world and all its creatures into a Las Vegas buffet. That was Phorusrhacidae, which are much more accurately known as "terror birds." According to the BBC, these flightless birds were basically just feathered, beaked velociraptors only without the charm and good looks. The terror bird became South America's top predator and reigned for nearly 60 million years, finally disappearing from the fossil record around the same time as megalodon.

One of the largest of these nightmarish creatures was Titanis, which was nearly 10 feet tall, had a top speed of around 43 mph (similar to an ostrich), and could snap the leg of a cow with its enormous feet and could also peck your head off. Literally. So if these things still roamed the Earth, well, there would be a ton of cows with broken legs and lots of humans missing their heads. In the plus column, most employers would be totally fine with telecommuting because no one would want to leave their house, ever.

Bigfoot is so elusive he evidently doesn't poop and disintegrates when he dies, and occasionally puts bear DNA in his hair samples just to confuse everyone who wastes their time and money looking for him. And if you don't find him, you can buy plenty of T-shirts and coffee mugs and fridge magnets that will at least let your friends know you gave it your best shot.

So what would the Bigfoot industry look like today if Gigantopithecus still roamed the Earth? According to National Geographic, this huge primate was 10 feet tall and weighed more than half a ton. It thrived in the warm tropical forests of China for around 6 to 9 million years, then the last Pleistocene ice age rolled around and Gigantopithecus died out because as the climate changed and forests gave way to savannas, there wasn't enough food to maintain a large population of calorie-hungry beasts of gigantic proportions.

Fortunately, Gigantopithecus did the smart thing — it caught a boat to southern Oregon and set up camp in the woods where it learned to emulate the haunting yet melodic call of the reality television producer. Just kidding. It did no such thing and neither did any other primate, except for humans attending the Oregon Shakespeare festival.

It's at least some small comfort that most of these creatures never shared the Earth with human beings — they vanished long before human beings took those tentative first steps out of Africa. And a good thing, too, because if all these terrifying creatures had been roaming the African landscape, the ancestors of human beings would have never come down from the trees.

Don't relax just yet, though, because at least one perfectly-capable-of-eating-humans creature did share the world with people, and it wasn't really that long ago, either. The Haast's eagle lived in New Zealand and was still flying around being terrifying as recently as 500 or 600 years ago. According to New Zealand Birds Online, Haast's eagle had a wingspan of nearly 10 feet and an arrangement of feet and claws that rivaled a modern tiger. It probably ate Moa, which were large, flightless birds that became extinct around the same time as the Haast's eagle did.

Here's where it gets extra-super-scary — native New Zealanders have an oral tradition that includes descriptions of Haast's eagles actually attacking human children, so we don't have to even imagine all the ways this predator might have been dangerous to people because it was actually, literally dangerous to people.

No matter how hard we try, human beings still haven't been able to snuff out racism. So what would life on planet Earth be like if we also had species-ism to deal with? What if Neanderthals still roamed the Earth. Would we be ignoring their job applications, calling the cops on them for barbecuing in the park, and generally making life for them uncomfortable and dangerous?

Well, if Homo sapiens can't learn to get along with each other, it seems pretty unlikely that they could learn to get along with other types of humans. On the other hand, perhaps the presence of similar but fundamentally different types of humans would be humbling. Maybe we wouldn't have grown to think of ourselves as a completely unique and superior species, and maybe as a result of that we'd be much better caretakers of our planet.

According to Real Clear Science, Neanderthals disappeared 30,000 years ago, so we won't ever know what our relationship with our close cousins was actually like — which makes it hard to speculate about what it might be like if Neanderthals still lived. It is a pretty safe bet, though, that Neanderthals would wreck life as we know it ... but let's just pretend that it wouldn't be in a bad way.

Quick, name the biggest, baddest dinosaur to ever walk the earth. Unless you are a dinosaur nerd, your answer was almost certainly "the T-Rex." But this dinosaur makes T-Rex look about as fierce as the plastic "Toy Story" T-Rex. The biggest, baddest dinosaur to ever walk the Earth was Spinosaurus aegyptiacus, which was 50 feet long. Compare that to T-Rex, which was a mere 40 feet long, though, to be fair, both dinos were equally rotund, weighing in at around 7 tons.

According to Reuters, besides its hearty appetite, Spinosaurus didn't really have a whole lot in common with its smaller, Hollywood-darling cousin. It was a quadruped, for a start, and is, in fact, the only carnivorous dinosaur we know of that walked on four legs instead of two. It was also semi-aquatic and preferred to eat fish. But not like a nice salmon sashimi or a shrimp cocktail or something in reasonably small portions, no — Spinosaurus ate sharks and crocodiles and, as Reuters likes to say, "car-size fish." So, first you will need to absorb the idea that car-sized fish were a thing before then contemplating what it would be like if Spinosaurus fell through a portal and started eating literally everything in the sea.

Footnote: some dinosaurs were bigger than Spinosaurus aegyptiacus, but they weren't predators.

This animal wasn't exactly a wolf. In fact, it wasn't exactly even remotely like a wolf, judging by its freakishly large head and weird, stripey butt, though the stripey butt is just one artist's idea about what Andrewsarchus might have looked like. The truth is that no one actually knows, because the only evidence that this huge predator even existed is a single skull someone found in Mongolia in 1923. Still, a skull does tell you a few things — Andrewarchus had a three-foot-long head, could have been the largest terrestrial mammalian predator that ever lived, and strongly resembled the Rodents of Unusual Size that thwarted Wesley and Buttercup's escape through the Fire Swamp.

According to ThoughtCo, Andrewsarchus lived roughly 35 to 45 million years ago during the Eocene epoch, and it may have weighed up to 2 tons, which is about the mass of two draft horses. This is all just based on that giant head, though, and it's actually possible that Andrewsarchus had a disproportionately large head propped atop a laughably small body, which would make it somewhat less impressive. But hey, it's really the teeth and jaws that matter most when evaluating the Earth-wrecking potential of a large predator, so it's unlikely you'd be laughing at Andrewsarchus' stupid-looking body while it was busy separating your disproportionately small head from your disproportionately small shoulders.

No list of extinct creatures that would wreck the Earth if they were alive today would be complete without the T-Rex, which was really bad at doing push-ups but made up for all of that with jaws that had a bite force of around 6 tons, enough to make scientists wonder why this famous predator didn't break its own skull when it bit down on its prey. (A recent study concluded that the T-Rex's skull was so rigid that it could resist all the bite force exerted by its powerful jaw muscles.)

Anyway, T-Rex may not have been the largest known dinosaur predator to ever walk the Earth, but it doesn't really matter because if turned loose upon the modern world, it might easily decide humans are on the menu. (And really, why wouldn't it?) You've seen "Jurassic Park" — no Jeep, restroom stall, or rotunda would be enough to separate a hungry T-Rex from its prey, and it's kind of doubtful the average three-bedroom, two-bathroom home in the suburbs would offer a whole lot of protection, either. In fact, according to National Geographic, this 40-foot long predator had 60 8-inch-long serrated teeth and was big and bad enough that it would probably eat other T-Rexes in tough times.

Most of the extinct animals that still terrify us today were predators, but let's not forget that even docile, plant-loving animals can be destructive and could have world-wrecking potential if they suddenly decided to embark on a mass migration through a time portal.

One animal we probably don't want coming through a portal is Argentinosaurus, the largest known land animal ever. Sure, it would be really cool to see one of these things in a zoo or something, but think about the potential destruction that could be levied by an animal that is 115 feet long and weighs 150,000 pounds. No one has really done any analysis of how much food an animal that size requires, but a research assistant at the University of Bristol at least had an educated guess — Argentinosaurus may have eaten around 1,875 pounds of plant matter each day, which translates into around 880 pounds of poop.

So let's imagine that just one of these dinosaurs ended up in a cornfield. Now let's imagine a whole herd of them ended up in a cornfield. It wouldn't take long for the farmer's cornfield to disappear, and there wouldn't be much anyone could do to stop it short of asking the military to drop a couple of bombs on the offenders. On the flip side, the farmer would have plenty of fertilizer available for next year's crop, so there's at least that.

The biggest animal to ever walk the Earth was a dinosaur, obviously, but prehistoric mammals reached some seemingly impossible sizes, too. According to CNN, paleontologists recently discovered the fossilized remains of a giant rhino in the Linxia Basin of northwestern China. This previously unknown species has since been dubbed the largest known land mammal.

The Linxia giant rhino measured 23 feet tall at the top of its head and was 26 feet long from snout to tailtip. Just to put that into perspective, a medium-size elephant is only about half that tall, so if you stacked two elephants on top of each other you'd have a couple of really angry elephants, but you'd also have a stack of animal flesh that was roughly the height of a Linxia giant rhino. You'd also have to put another stack of two elephants behind the first stack of elephants in order to achieve the total length of a Linxia giant rhino, and you'd also need a couple of extra elephants standing by in order to achieve the total weight of a Linxia giant rhino (24 tons).

Now, given that modern rhinos have a reputation for being ill-tempered and sometimes like to charge people in stripey safari jeeps, we might be able to assume that Linxia giant rhinos would have a similar dislike of humans, although they might have been big enough that they'd think of us merely as irritating insect-like things that could be stomped out of mind. Either way, Earth-wreckers for sure.

A giant predatory dinosaur is a terrifying thing to imagine, but mammalian predators are scary on a whole different level, maybe because they're just a little too familiar, just a little too real. Animals like the T-Rex and Spinosaurus are so unlike anything in human experience that they might as well be dragons.

If you were to meet Simbakubwa kutokaafrika on the savanna late at night, well, let's just say it would eat you long before you managed to figure out how to pronounce its name, which means "big lion from Africa" in Swahili (via CBS). According to a 2019 paper published in the Journal of Vertebrate Paleontology, Simbakubwa kutokaafrika was a Hyainailourine hyaenodont, which were some of the largest mammalian carnivores known to science. Despite the name, members of the hyaenodont weren't related to modern hyenas, and didn't look much like them either. In fact to a modern human they'd probably look somewhat familiar — a little bit like lions and a little bit like bears (via Discover), but much, much bigger than both. In fact, researchers think Simbakubwa kutokaafrika may have weighed around 3,300 pounds, roughly three times as much as a polar bear, which according to The Guinness Book of World Records is the largest terrestrial carnivore that exists today.

Because piranhas aren't scary enough already, how about a "mega piranha." Why not? Prehistory did love to up the ante on our most terrifying creatures with their own super-sized versions. Hopefully, Future History doesn't get any ideas from Prehistory, although the way things are going, the only creatures that will still be around for Future History to muck with are cockroaches and house mice.

Anyway, yes there was once a piranha large enough to be dubbed "megapiranha." According to ThoughtCo, it lived 10 million years ago, was roughly 5 feet long, and weighed between 20 and 25 pounds. Like the piranha known and loved today, it lurked in murky South American rivers, where it mostly preyed on fish because there weren't any humans around to accidentally fall into the water while for some reason canoeing around in megapiranha-infested waters.

Let's be fair, though, there's only one way these things could possibly wreck the Earth if they still existed. Supervillains would put them in swimming pools, attach laser beams to their heads, and then confess to all of their supervillain crimes while dangling Austin Powers over their giant, snapping jaws. This wouldn't completely destroy civilization or anything, but it would at least make supervillains more effective. So who knows, perhaps the megapirhana could indirectly lead to the destruction of the moon or the emptying of the ocean or whatever it is supervillains like to do with their time.

Nothing really runs around in massive herds anymore. Before colonial times, tens of millions of bison (via Fish and Wildlife Service) roamed the grasslands of the Midwest in massive herds, but no more. That is an awful thing for the buffalo, but there are plenty of people living on the Great Plains who probably wouldn't like to see the great herds return. Regardless of how you feel about civilization, it would be pretty hard for humans to carry on doing the things they do if suburbia was at risk of random trampling by massive herds of bison.

And massive herds of bison don't even begin to compare to what a herd of Maiasaura would have been like. According to ThoughtCo, these duck-billed dinosaurs grew to be about 30 feet long, weighed about 5 tons (compared to half to 1 ton and 10 to 12 feet for an adult bison, via National Wildlife Federation), and lived in massive herds. In fact it's likely that their herds may have numbered in the thousands, so imagine that crashing through your backyard fence on a Sunday morning. Now let's bring back Maiasaura's primary predator — Troodon — and imagine what it would be like if the Maiasauras weren't just after your tomatoes but fleeing en masse for their lives. If these animals still roamed the Earth, let's just say there wouldn't be a whole lot of room left for human neighborhoods.

Who doesn't love a kangaroo wearing boxing gloves, or, if you're more of a naturalist, a kangaroo leaping gracefully across the Australian Outback?

If your knowledge of kangaroos transcends those stereotypical images, you're probably aware that the boxing gloves should go on the kangaroo's hind feet because those are the parts that really pack a punch. In fact Popular Science says there is 759 pounds of force in the kick of a red kangaroo, and never mind that the claws on the kangaroo's foot could also potentially eviscerate you (via Slate).

Anyway, here's a fun fact — Propleopus oscillans, also called the giant rat kangaroo, lived during the Pleistocene, weighed up to 150 pounds, and probably ate meat, as per PBS, maybe even people meat, since there's a good chance that it was still around when humans arrived in Australia (via the Australian Museum). Now granted, some modern kangaroos do get that big, but they're vegetarians, so if you don't try to catch them and put boxing gloves on them you're probably safe.

To be fair, Propleopus oscillans was a rat kangaroo, not an actual kangaroo. According to PBS, its closest living relative is the musky rat kangaroo, which weighs only 18 pounds. And the musky rat kangaroo doesn't hop, so it probably didn't kick with as much force as a red kangaroo. If you were imagining a predatory kangaroo hopping towards you with its mouth open, you can at least get rid of that terrifying image.

Some weird-looking things have swum in the sea. Many of them still swim in the sea. Others had crazy adaptations that may or may not have been too crazy to support their long-term existence.

You've probably seen pictures of Helicoprion, though you may not have seen the right pictures. In fact according to the authors of a study published in Biology Letters, there have been at least a dozen different theories about what Helicoprion looked like, specifically where on its body the "whorl" was supposed to go. The whorl, by the way, is the large wheel of razor-sharp teeth that through the years have been placed on Helicoprion's nose, back, lower lip, and sticking out of its mouth like a tongue. It's only been in the last decade or so that scientists have finally settled on where the whorl probably goes: tucked away inside its mouth like the blade of a rotary saw, which makes sense because it had pretty much the same purpose as a rotary saw.

According to Scientific American, Helicoprion probably eviscerated its prey with that bottom row of teeth, which acted like a slicing device when the beast closed its mouth.

Contrary to what most people assume, Helicoprion wasn't a shark — it was a chimaera, which is only distantly related to sharks. And it might not wreck the world if it was alive today, but it would certainly wreck the limbs of many, many surfers.

Unless you watched "The Lion King" as a very small child, you probably don't think hyenas are that terrifying. After all, they kind of just slink around making that ridiculous sound, stealing meat from lions that usually just look annoyed. But the image is kind of deceptive. Hyenas can be pretty menacing, though maybe not quite as menacing as their extinct relative, the giant short-faced hyena known as Pachycrocuta brevirostris. According to a study published in Quaternary Science Reviews, this was the largest hyena to ever live and "perfectly embodied the distinctive bone-cracking adaptations of this mammal family." Yikes.

Pachycrocuta brevirostris lived during the Pleistocene and may have even coexisted with early humans, according to Live Science, though probably not for long given the whole "bone-cracking" thing. It weighed about 250 pounds (via Quarternary International), which according to PBS is roughly the size of a small female lion and about 60 pounds more than the largest spotted hyena (via National Geographic).

Despite its size, some scientists believe that Pachycrocuta brevirostris didn't have the bite strength to be a hunter and was probably more likely to be a scavenger. If that's true, the lions it stole from almost certainly experienced some very different emotions than just feeling kind of annoyed.

When thinking about extinct creatures with the potential for widespread destruction, T-rex in "Jurassic Park" or Discovery Channel's megalodon come to mind. The creatures we should really be worried about, though, are the ones you can't see.

Bacteria are some of the most vicious creatures on the planet, capable of a kind of widespread destruction and devastation that even T-rex would never cause — because T-rex actually had the capacity for eventually feeling full.

According to a study published by Proceedings of the National Academy of Sciences, the Black Death was caused by Yersinia pestis, a bacteria that can still be found living in the fleas that infest critters all over the world. This includes the Norway rats that live in your tool shed and that cute little chipmunk you gave a potato chip to while you were camping last summer.

The strain that caused the Black Death between 1347 and 1351 is now extinct, though, and no one can really say what would happen if it got resurrected. Most people in the developed world aren't exposed to a lot of plague-carrying fleas, and the authors of a study in Antimicrobial Agents and Chemotherapy say Black Death is also treatable with antibiotics, so it's possible it wouldn't cause much harm in the developed world. In the less developed parts of the world, though, it could be devastating.

Scientists are already toying with the idea of bringing back the mammoth. Some people even argue that bringing the mammoth back might somehow slow down carbon emissions and resurrect ancient ecosystems (via Statesman). If that sounds a little far-fetched to you, you're not the only one who feels that way. And even if it's true, there are some very good questions about what kind of harm it would do to efforts to save other species if our conservation dollars were spent on resurrecting species that have been gone for thousands of years.

In a study published in the journal Nature Ecology & Evolution, researchers argued that de-extincting species could result in a net biodiversity loss, mostly because de-extinction would be so expensive that it would leach money from efforts to save animals that still exist but are on the brink of extinction. So if the mammoth existed today — if it were literally brought back from extinction — it would wreck other species' chances of survival and possibly even wreck ecosystems. Some scientists like Kent Redford, quoted in U.S. News and World Report, even think certain de-extincted species could end up becoming invasive. That's a very real return to existence that's worth a good, long ponder.