15 Of The Most Terrifying Prehistoric Creatures Ever Discovered

The animal kingdom is a truly wonderful thing. It contains all types of living creatures that live in a huge range of different habitats and environments, making them all vastly different from one another. For the most part, humans get along relatively peacefully with the other organisms that surround us in our everyday lives. This is simply because there are few animals that are a danger to us and those that are potentially threatening are usually located well away from any human population.

That isn’t to say that there aren’t creatures that are frightening. People are scared of all types of things, ranging from phobias of insects and spiders, to being alarmed by huge carnivores such as crocodiles, sharks and bears. However, even these monstrous beasts are nothing compared to the prehistoric monsters that once lived. Fortunately, most of the truly terrifying creatures that once roamed the world are now extinct, because they are truly exceptional in their ability to cause nightmares.

Some of the examples in this article are horrific simply because of their size, while others have gruesome appearances or barbaric hunting methods that make them something that no one would ever want to encounter. Whatever the case, it is painfully obvious that we wouldn’t have been able to survive around such creatures (but they would make excellent material for horror movies).

15 Azhdarchid

Azhdarchid was a species of Pterosaur, a flying reptile that many people consider to be winged dinosaurs. This is inaccurate however, with the extinct creatures actually belonging to a different family of organisms much like the gigantic marine reptiles that were around at the same time.

14 Entelodon

Often known as the killer pig, the entelodon is an extinct form of pig-like omnivore that lived around 37 million years ago. These huge creatures could be found across North America, parts of Europe and even Asia. Like their modern-day relatives, entelodons had a diet that consisted of both meat and vegetation, meaning that they had incredibly sharp teeth. However, they also differed significantly thanks to the large size of their cloven hooves.

13 Liopleurodon

Unlike the vast majority of marine reptiles that are alive today, that range from turtles to alligators, liopleurodon was a truly massive creature. It lived in the oceans for around 5 million years before dying out some 155 million years ago. While accurate estimates of its size are difficult to calculate due to the small amount of fossil evidence available, most experts believe they were likely to be around 30 feet long. This would mean that they would weigh an astounding 3,500 pounds and would be able to hunt almost any other creature living in the waters in which it roamed.

12 Gigantopithecus

The gigantopithecus has jumped into the public consciousness in recent times, despite being relatively unknown for hundreds of years, thanks to the fact that it appeared in Disney’s live-action version of The Jungle Book. They were essentially giant orangutans that lived around 100,000 years ago in the forests of India and China. In fact, their size was so immense, with fossils indicating that they could have been as tall as 10 feet and weighed upwards of 1,100 pounds, that they are the biggest ape to have ever existed.

11 Xenosmilus

Although many people have ideas about sabretooth tigers simply being very large cats, the xenosmilus was different in that it wasn’t just large but built heavily with very large muscles. This gave it an appearance of a cross between a leopard and a bear. This unique look and build meant that it hunted in a different way to the vast majority of saber-toothed cats. Using its distinctive cookie-cutter jaw, it would simply use its strength to tear huge chunks of muscle and flesh from its prey so that it would slowly die from blood loss as it tried to escape.

10 Aegirocassis

Only found when remains were uncovered in Morocco in 2014, the Aegirocassis is a type of sea creature that is closely related to modern day lobsters. It was capable of growing in excess of 6 feet long, making it around the same size as a fully grown adult human. Dr Allison Daley, of Oxford University, said: “This would have been one of the largest animals alive at the time.”

9 Argentavis Magnificens

Fossil records demonstrate that argentavis magnificens was likely to be the largest bird that has ever taken to the skies. Standing as tall as an adult human and weighing as much as 180 pounds, it was unlike any bird that is alive today. Unlike other large avian species though, it was unlikely to act as a predator, as it wasn’t built to specialize in hunting prey. Experts believe it is more likely that the huge creature would scavenge its food.

8 Arthropleura

There are few living creatures that scare people more than bugs and insects. They are such terrifying things that many horror movies prey on this fear by creating huge monsters that are simply giant versions of common creepy crawlies. The arthropleura could then be described as a horror movie made real, as it was a huge millipede that could grow to a size of up to 8 feet long. Living some 299 million years ago, they were so big that they would have had no natural predators and are considered the largest known land invertebrates that the planet has seen.

7 Titanoboa

The largest snakes alive today are capable of growing to around 25 feet in length in certain circumstances, but the Titanoboa would put them all to shame. This is because it weighed more than a ton and measured an incredible 50 feet in length. "Never in your wildest dreams do you expect to find a 14m boa constrictor. The biggest snake today is half that size," said Dr Carlos Jaramillo, a scientist at the Smithsonian Tropical Research Institute.

6 Meganeura

Dragonflies are not particularly frightening creatures, though some do have a phobia of them. Yet few would probably fail to be terrified of Meganeura, a species of dragonfly that was as large as a child. Having lived around 300 million years ago, the flying insect had a wingspan of 26 inches and a body length of around 1 foot. Like its modern day relatives, it was a carnivore that would most likely prey on small invertebrates and amphibians.

5 Dunkleosteus

While there are certainly some very ugly and scary fish alive today, such as piranhas, they pale in comparison to the Dunkleosteus. This giant fish lived about 360 million years ago and is one of the largest fish to ever live, capable of growing up to 20 feet long and 1 ton in weight. Its great size meant that it was an apex predator that was protected from danger thanks to armor plating around its head.

4 Carbonemys

Discovered in 2005 by a team of researchers in a Colombian coal mine, the Carbonemys is an extinct genus of giant turtle that lived 60 million years ago. With a shell that was almost 6 feet long, its entire body was around 10 feet in length. The huge creature would have weighed 1 ton, making it a similar size to a small car.

3 Gorgonopsia

Gorgonopsia is a species of therapsid that are ancestors to modern day mammals. They were essentially a cross between reptiles and mammals that roamed the earth some 250 million years ago. Unlike many other creatures at the time, Gorgonopsia had specializations that included unique tooth shape and powerful hind legs.

2 Sarcosuchus


Although it isn’t technically a crocodile, Sarcosuchus closely resembled the modern day reptiles, with its long body and scaly appearance. Unlikely saltwater crocodiles though, this example was able to grow to about double the size. In fact, some scientists believe that it was capable of reaching even greater sizes as it would continue to grow throughout its lifespan, enabling it to surpass 40 feet in length.

1 Megalodon

Sharks are already one of the most terrifying creatures that live on the planet today. As well as a somewhat alien quality that they possess, they are also capable killers with horrific teeth that are capable of giving anyone nightmares. Megalodon though takes the idea of a shark to the next level. These huge sea creatures were alive approximately 2.5 million years ago and are now regarded as one of the biggest and most powerful killers in history.

The giant shark was able to reach a length of almost 60 feet and looked like an exaggerated version of the great white shark. Most frightening of all was the huge jaw that held teeth that were up to 6 inches long and 4 inches wide. Due to its large size, the shark was able to eat a huge variety of prey, including whales, giant sea turtles and dolphins.


Give TheRichest a Thumbs up!

Looking for an AD FREE EXPERIENCE on TheRichest?

Get Your Free Access Now!

More in Most Shocking

15 Of The Most Terrifying Prehistoric Creatures Ever Discovered