7 Scary Extinct Animals That Were Absolute Terrors
There are plenty of terrifying animals alive today — grizzly bears, condors, boa constrictors, great white sharks and giant hornets, to name just a handful. But there are also some very scary extinct animals that would cause modern-day humans to run away screaming.
If you're okay with chancing some bad dreams tonight, read on to learn more about several of the most frightening animals to have ever roamed the earth.
Arctodus simus: The Giant Short-Faced Bear
One of the most dangerous extinct animals was the giant short-faced bear (Arctodus simus). A formidable predator of North and South America, it weighed more than 1,500 pounds (680 kilograms) and stood up to 12 feet tall (3.7 meters) on its hind legs.
The giant bear's massive size and powerful jaw made it one of the most dangerous predators of its time, capable of taking down large prey and competing with other apex predators.
Experts say the animal could probably run faster than 40 mph (64 km/h) to catch its meals. That's similar to the top speed of present-day racehorses, meaning human beings would have had no chance at escaping this prehistoric nightmare.
Phorusrhacos: The Terror Bird
Paleontologists call the extinct birds of the Phorusrhacidae family in South America the "terror birds," ranking them among the planet's scariest extinct animals.
With powerful beaks and sharp teeth capable of inflicting deadly wounds, these creatures were natural predators, preying on other animals and almost certainly instilling fear in the earliest aboriginal people who might have encountered them.
Imagine a 10-foot-tall (3-meter-tall) Phorusrhacos using its huge beak like a hatchet against its victims. (We'll pass on that experience, thanks.)
The terror birds were mostly flightless, but they made up for their lack of flight with the ability to run up to 60 mph (97 km/h). For reference, ostriches, which are the tallest living birds, max out at 9 feet (2.7 meters) tall and can sprint up to 43 mph (69 km/h).
Titanoboa cerrejonensis: The Giant Snake
Among the largest snakes to have ever existed, Titanoboa cerrejonensis is a prehistoric animal straight out of your darkest nightmares. It belongs to the Boidae family of animals, which evolved in North and South America during the Cretaceous period.
This giant snake could reach lengths of up to 42 feet (nearly 13 meters) and weighed over a ton (more than 1,000 kilograms). For reference, even the longest anacondas ever discovered have never surpassed 30 feet (9 meters). The mouth and head alone of the extinct animal may have been longer than 2 feet (0.6 meters).
Titanoboa likely lived in or very near the water, where these extinct animals could ambush and kill other species. Their huge size and powerful bite force allowed them to constrict and consume large prey, making them one of the most dangerous extinct animals of the prehistoric world.
Smilodon fatalis: The Saber-Toothed Tiger
Saber-toothed cats, including the famous saber-toothed tiger (Smilodon fatalis), were powerful predators that lived during the early Miocene and Pliocene epochs. With intimidating incisors measuring about 1 foot (0.3 meters) and a powerful jaw, these creatures were adept at taking down large animals.
Weighing up to 750 pounds (340 kilograms), this extinct animal was a superior hunter, electing to catch its prey off guard versus running it down. While it held the prey with its front legs, it used its sharp teeth to slash the animal's throat or stomach. Then it left its prey to bleed out, returning to feast once the animal was dead.
Otodus megalodon: The Giant Shark
When thinking about the most dangerous extinct animals, you can't overlook the Megalodon (Otodus megalodon), a giant shark that could reach lengths of up to 60 feet (18 meters), making it a truly formidable predator of the oceans.
This prehistoric shark, which swam in the same waters as large whales, possessed the most powerful bite force of any marine creature in history.
Paleontologists have found its teeth marks on fossilized whale bones, suggesting Megalodon ate the faces off prehistoric sperm whales. And Megaladons weren't picky eaters: These distant relatives of today's great white shark also preyed on baleen whales.
Deinosuchus rugosus: The Terrible Crocodile
Deinosuchus rugosus, which paleontologists refer to as the "terrible crocodile" or "terror crocodile," easily earns a place on this list of the most dangerous extinct animals. It lived during the Cretaceous period and was once the largest predator in North America.
Deinosuchus grew up to 40 feet (12 meters) long and could range from 13,000 to 15,000 pounds (roughly 6.5 to 7.5 tons), or about the same weight as a fully grown Tryannosaurus rex — another scary extinct animal (although the timelines for these two extinct species did not overlap).
With an incredibly powerful bite force, the Deinosuchus was capable of crushing the bones of even the biggest dinosaurs. It also likely fed on prehistoric birds, turtles, fish and other extinct animals.
Arthropleura armata: The Gigantic Millipede
In the Carboniferous period, the Arthropleura (Arthropleura armata), a gargantuan millipede, roamed the Earth with between 32 and 64 jointed legs.
This terrifying creature is the largest land invertebrate ever discovered, capable of growing up to 8 feet (2.4 meters) long and nearly 2 feet (0.6 meters) wide, with articulated armored plates covering its entire body. It may have weighed close to 110 pounds (50 kilograms).
Although Arthropleura likely fed primarily on plant matter and maybe smaller invertebrates, its massive size and intimidating appearance make it one of the scariest extinct animals to have ever existed.
We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.
3: Ambulocetus natans
There you are, 50 million years ago, enjoying a hot Eocene afternoon at the seashore and watching a foxlike prehistoric rodent cool its paws in the mud at the water's edge. Suddenly, a monstrous beast explodes from the depths, seizes the hapless fox-thing in its massive jaws and disappears beneath the waves. All is quiet again. The local birds return to their business. It's as though nothing ever happened. You've just glimpsed the probable hunting methods of an Ambulocetus natans, a 400-pound (180 kilograms), 10-foot-long (3 meters) "walking whale."
Basically, an Ambulocetusnatans was a mammalian version of a crocodile but with longer hind legs to power it through the water. Like crocodiles and hippos, it had widely spaced eyes that sat near the top of the skull — ideal for lurking invisibly in the shallows until some tasty victim comes along. Paleontologists think it waddled around a bit on land but probably spent the bulk of its time in shallow coastal waters. With webbed feet and hearing mechanisms well adapted for life underwater, A. natans forms part of the important fossil record that tells us how whales inched their way from land to sea over millions of years [source: Thewissen et al.].
2: Squalodontidae
Seventeenth-century Italian Agostino Scilla was one of those old-school polymaths who excelled at everything. An accomplished professional painter, he was also a geologist and paleontologist. In fact, he was among the first scholars to study and document fossils. His 1670 drawing and description of a fossil from Malta was one of the first in scientific literature.
That fossil was a jaw belonging to what is now called a Squalodontid, and it included three sharp, serrated teeth. Squalodontidae, which were about 10 feet long (3 meters), are also called "shark-toothed dolphins," and their teeth are truly menacing. Modern dolphin teeth are nonthreatening little bumps that have the same shape from the front to the back of the jaw. Squalodontidae, however, had large, curved, sharp fangs in front and serrated, triangular cheek teeth for slicing their prey up into manageable chunks.
Once upon a time, paleontologists theorized that modern dolphins were descended directly from squalodons, but it now seems more likely that these sleek predators, who prowled the seas between 28 million and 15 million years ago, died out before passing on their DNA [source: Fordyce].
1: Leviathan melvillei
Your modern sperm whale may seem to be a mighty beast. After all, Moby Dick was one of them, and he sank a whaling boat. Although Melville based his great novel on a true story, he fudged some facts to make his whale scarier. The truth is that sperm whales spend most of their time diving deep while on the hunt for cephalopods like squid and octopuses. And although they have some peglike teeth, they actually use suction to hold onto their prey.
But in 2010, researchers in Peru uncovered the remains of a gigantic sperm whale dating back 12 million years to the Miocene era. Measuring more than 50 feet (15 meters) in length, its head alone was nearly 10 feet (3 meters) long, and its powerful jaws were lined with 12-inch (30.4 centimeters) teeth. Its prey? Baleen whales. The paleontologists who found this monster named it for Herman Melville, which seems fitting. After all, as one of the largest known predators to have ever existed, Leviathan melvillei was the force of nature Melville wanted Moby Dick to be [source: Urbina].
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Original article: 7 Scary Extinct Animals That Were Absolute Terrors
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