Have you seen the Jurassic Park movie series as a child? Would you be scared of the dinosaurs if they were resurrected from their fossils again? Presumably, a meteor crash forced the dinos’ extinction. But did you know about all the other animal species as equally life-threatening as the dinosaurs, or even worse, who made the extinction list?

Our planet had seen the most significant extinctions ever since the era when dinosaurs lived. If you are scared of wild cats and badgers popping up in your backyard, you might get nightmares if you witness the following 14 extinct animals appear in your locality.

Without further ado, let’s look at these 14 extraordinary extinct animals.

1. Haast’s Eagle

Starting off the list with this giant eagle, you wouldn’t want to encounter as big as 2.5 meters with both wings stretched out and weighing about 15 kilograms. This giant eagle was the most significant prehistoric predator endemic to New Zealand’s fauna. Near-complete skeleton findings show that it had the body and wings of a giant eagle, legs, and bill larger and more robust than the most significant living vulture species, and feet and claws as big as that of a tiger.

Before humans colonized New Zealand about 750 years ago, the most significant inhabitants were birds like the Haast’s eagle and the moa. This giant flying beast became extinct almost 500 years ago and was never a scavenger as believed till the last decade. Scientists believe that the Haast’s eagle became extinct due to the destruction of its habitats and the early Polynesian settlers’ extinction of its prey species.

These predators probably preyed on the flightless smaller birds and, in some unfortunate cases, the ancestral human babies, according to the Maori mythology, which mentioned the legendary pouakai or hokioi, a bird giant and deadly enough to swoop down on people living at a higher altitude and killed babies from open fields. Encountering such a monstrous bird in your backyard chasing after the garden mouse wouldn’t be a great idea.

2. Arthropluera

If you are not a fan of millipedes and centipedes crawling around your flower bed, this one will surely give you nightmares. During the late Carboniferous period, about 340 million years ago to 290 million years ago, a giant millipede, about the size of a small car, flourished on the face of Earth.

An Arthropluera in Greek means “rib joints” and is known to be the largest invertebrates to have ever existed on Earth. It was endemic to the now areas of North America and Europe, with a size ranging from 0.3-2.5 meters long and up to 20 inches wide. That’s almost 8 feet tall – yikes!

The sight of such a monster crawler might paralyze you if not for its heavy body weighing up to 50 kilos. Having a millipede at the top of the food chain is a very uncommon phenomenon, but when it lived, no other land crawler stood a chance in front of this giant. Despite its large size, this creature was herbivorous, one of the first mainly herbivorous terrestrial animals. It had big strong jaws but was unlikely to be poisonous as a defense mechanism.

They were able to grow so large because oxygen levels were 50% higher in the atmosphere of the Carboniferous could support larger species whose circulatory system was not as efficient as those of mammals and other species. Thanks to the climatic changes that wiped off these giants before humans evolved! Therefore, it allowed this creature to grow to enormous sizes. I would not prefer encountering one any day!

3. Deinosuchus

If you think crocodiles are scary, think again because this predator reptile from the Late Cretaceous Period will knock you off your imaginations. This ancient behemoth was not a dinosaur but a 10-meter-long alligator that weighed up to seven tonnes—as much as a full-grown elephant! With its snapping jaws, Deinosuchus was the largest predator in its ecosystem, and it made snacks out of the duckbills, sea turtles, and horned dinosaurs that plodded near prehistoric marshes. A dino-eating giant alligator!

The name Deinosuchus translates as “terrible crocodile.” It is derived from the Greek deinos, “terrible.” Soukhos, “crocodile.” These giant reptiles existed between 82 to 73 million years ago in the coastal swamps of the U.S. and Mexico, along with the Atlantic coastal plain from New Jersey to Mississippi. Matching the size of the most feared of all dinos, i.e., the T-Rex but beating it in weight makes this alligator a potential predator for almost everything within its vicinity.

Given its size and an estimated bite force of more than 10 tonnes, these “terrible” alligators might have preyed on T-rexes, but it is not known to date. Scientists have found dino fossils with bite marks of this giant reptile on the bones suggesting how mutilated it might have left the dinos once breaking into a fight.

You might not want to imagine what it could do to a human being; neither do I.

4. Entelodon

Wild boars look scary, but nothing beats the Entelodon, immortalized in prehistoric nature documentaries as the “Killer Pig.” It was about the size of a modern cow; it had a prominent pig-like face with bone-supported wattles like warts on both of its cheeks and a long protruding snout studded with deadly-looking teeth. Like many mammals of the Eocene epoch period – around 30 million years after the dinosaurs went extinct, Entelodon also had a tiny brain according to its size and was probably not the brightest omnivore of its habitat.

The broad distribution of Entelodon species across Eurasia reveals that it was a successful animal.‭ ‬This success may have been because of its omnivorous diet, which means that it could switch and adapt to different food sources.‭ ‬Smart or not, these omnivores used to be about 10 feet long and weighed 1,000 pounds, which didn’t need any intelligence to catch small prey. Additionally, their large size meant that fully grown adults were unlikely to be attacked by predators. Still, Entelodon may have also been able to physically drive these predators away from their kills and feed upon the carcasses of animals themselves.

It is impossible to relate these beasts with the cute pink farm pigs, and that’s true. Recent studies have expressed it to be closer to the ancestors of hippos. Encountering an Entelodon wouldn’t just be a nightmare – it would be a massacre!

5. Smilodon

Domestic cats look so cute asking for a belly rub, but their playfulness sometimes causes painful scratches and bite wounds. Do you think a cat scratch is scary? Ever thought about what a Smilodon could do to your body? Often called the “saber-toothed cat,” a Smilodon comes nowhere close to a domestic cat. It had a body measurement close to a modern-day tiger and rose to a meter in height by the shoulders.

This menacing “cat” dwelled in the North, Central, and South American forests, brushy plains, and margins of woodlands before becoming extinct almost 13,000 years ago. It is called a “saber-toothed cat” because of its 7-inch-long canine teeth, which made a dreadful show on both sides of its face. This beast could open its mouth at an astounding 130 degrees, which is almost twice the gape of modern cats – imagine the size of animals it used to prey upon!

This beast was mainly designed for ambush hunting. Nobody wants to be ambushed by such a freaky beast! Feeding on large mammals like bison, giant sloths, young mammoths, and mastodons, the Smilodon did not go for lighter animals as it was too heavy to give its prey a death chase.

6. Hyaenodon

After cats, let’s discuss something about dogs. Even if we assume that you like dogs, there would certainly be people in your friend circles who aren’t dog lovers. They would get jumpscares on encounters with a barking dog. Would you like to meet a beastly dog from ancient times? Meet Hyaenodon, the predatory canine-like creature from about 25.1 million years ago.

Despite its name, Hyaenodon is not closely related to hyenas and dwelled in the Redwood Forest areas in areas of what is now North America and Eurasia. It wasn’t relatively small to imagine for a 6-meter-long body and a weight of about 500 kilos. Though other terrestrial animals exceeded its size, its terror was well spread amongst its prey.

It is better to stay away from such a “dog” for survival! The ultimate reason behind it becoming extinct might be the larger predators. They hunted in groups denying the Hyaenodons their prey for quite a long time – millions of years, eventually leading to their overall extinction.

7. Kelenken

The sight of flightless terror birds in Jurassic Park is enough to make one anxious, let alone encountering one in real. Say hello to the Kelenken, a giant flightless predator bird from around 15 million years ago residing in the South American forests. The enormous skull of any known bird is 28 inches in length, mainly its beak of 18 inches, and it belongs to the Kelenken. Can you imagine a bird this big? An enraged ostrich isn’t enough to compete with this giant too!

This bird, rather than flying, ran very fast, running up to 35 mph, 56.3 km/h. Good heavens! That’s like being chased by a small-sized bus. Being fast-moving, the beast most likely pursued and crushed prey under its massive beaks. It likely hunted rodents, deer, immature horses, llamas, sheep, sloths, and armadillos. Kelenken picked prey up in its jaws and vigorously shook them to break its spine. Yikes!

Nobody knows what terror would have befallen us if it still existed. The terror birds probably became extinct when the giant carnivore mammals, such as the saber-toothed cats and animals like ancestors of modern wolves, migrated from North America to South America. It might have happened when the Panama bridge appeared about 2.5 million years ago, and the competition would have been tough for these birds with the prehistoric “dogs” and “cats.”

8. Gigantopithecus

Fascinated about King Kong? They existed in reality, and it’s time to introduce the Gigantopithecus, the giant ape that existed around a million years ago while humans were evolving slowly from the apes. Giganthopithecus blacki is the scientific name for the species of Kong, and they dwelled in Southern China and the islands of Vietnam, Indonesia, and Thailand. And yes, Skull Island exists in reality in the Indian Ocean where Kong used to live.

I don’t think meeting a Kong would be a good idea in practice, assuming they weighed five times as much as an adult man and probably stood 3 m (10 ft) tall and weighed up to 500 kilos. Its enormous size probably required it to overeat, which somewhat occurred 6-9 million years ago. About a million years ago, after humans started evolving and discovering their worth, these gigantic apes fell short of their food habitats and faced extinction.

Another species of the giant ape is the Bornean orangutan Gigantopithecus which was King Louie from The Jungle Book. That species looks more like an orangutan and belongs to the same family of Gigantopithecus. Given their giant size, the shrinkage of forest areas forced them to face extinction due to a lack of food. No wonder King Louie wanted to know the uses of fire from Mowgli to help keep his species alive. 

9. Megalania

Any passing thoughts on lizards? What about a monitor lizard? What about a “giant” monitor lizard? Not so cool, right? Read about the Megalania from the Pleistocene period, inhabiting the Australian lands. Its size matches the Komodo Dragon; it is more closely related to lizards. Like these relatives, it’s likely Megalania was a vicious animal, and if that’s the case, it’s the largest venomous vertebrate ever to live.

Why would anyone even think of meeting this creature? It had a heavily-built body and limbs, and it had a massive skull and a jaw embedded with serrated blade-like teeth. Judging from its size, it would have fed on medium to large prey such as the giant marsupials, other reptiles and small mammals, and the birds, their eggs, and chicks.

The first-ever aboriginal settlers of Australia might have encountered this creature about 50,000 years ago, and humans might have been the reason these lizards faced extinction. Though most of the Australian land remains unexplored, chances might be there this giant lizard still walks through the uninhabited lands of Australia today!

10. Andrewsarchus

Have you ever felt confused about the species while looking at an animal? Meet Andrewsarchus for this experience. Its physical appearance and features highly confused people about which species has a close relation to this beast. Despite their canine-like appearance, Andrewsarchus was not related to modern scavengers, such as dogs, wolves, or hyenas. Strangely enough, they possessed hooves on their feet as opposed to claws. Their nearest modern relatives are hoofed animals like hippos and whales.

What the hell is it? Keeping aside the confusion, Andrewsarchus has been a scavenger and a dangerous predator for roughly 45 and 36 million years ago in Inner Mongolia, China. It stands as tall as a horse and has facial features matching a horse. It is believed that Andrewsarchus was about 6 feet high at the shoulder and about 12 feet long. That would make its weight anywhere from 500 to 1,000 pounds – goodness!

Known as the world’s largest predatory mammal to date, it hunts and scavenges, so it is better not to meet one in real, or you would be dead in no time.

11. Paranthropus

After coming across some beastly animals, let’s encounter a giant ape and jump into the “ape apocalypse” scenario for a while. Paranthropus lived as the primate apes in the African continent almost 2.2 million years ago, during which humans were slowly evolving.

Whereas the ancestors of humans were thought to be adaptable generalists, Paranthropus species, which evolved massive teeth and jaws for chewing hard vegetation, were thought to have hit an evolutionary dead end because they were too specialized to adapt to new food sources produced by Africa’s changing climate. Despite these apes being plant-eaters, their human-like sizes would scare the hell out of you.

Though the tallest one to date is only a little less than 5 ft and weighs about 54 kilos, a hairy ape with a human-like skull and massive jaws wouldn’t be a good encounter. Their skulls were relatively large, indicating an intelligent species, unlike the giant apes with fewer brain capacities.

12. Titanoboa

An ancestor of the today-known anaconda, the “snake of your nightmares,” is an extinct genus of giant snakes that lived in what is now La Guajira in northeastern Colombia. They could grow up to 13 m, perhaps even 16 m long, and reach a weight of 1,135 kg. If an anaconda can swallow a human, this one can swallow your entire family at once, along with your pets! If the movie Anaconda gave you nightmares, a Titanoboa would make you weak in the knees.

The Titanoboa shared its habitats with the giant turtle, feasting upon turtles and crocodiles, which co-existed in the swampy areas of South America. Like the modern green anaconda, they could not achieve much hunting on drylands. They could hold their breath for almost a crazy 45 minutes! That’s how they planned to lure prey near the water bodies for an ambush.

They flourished in hot and humid climatic conditions, and the decreasing global temperature resulted in their extinction around 58 million to 60 million years ago. Some anacondas have been reported to grow close to the size of ancient Titanoboa in recent times – oh, hell no!

As per the rising global warming, Titanoboa might come back to existence after the substantial evolution of the anaconda in warm and humid climate conditions. Nobody wants to be threatened by a giant lurking snake that big and dangerous!

13. Arctodus

The Arctodus, commonly called “short-faced bears,” is an extinct bear genus that inhabited North America from almost 2.5 million years ago until 10,000 years ago. Although bears look cute, they are one of the largest and heaviest predatory mammals. They reached over 11 feet when standing upright – even more significant than modern polar bears. Could they be any deadlier?

The Arctodus was a bone consumer and a hyper-scavenger with well-developed, strong teeth. These giant bears lived during the ice age in open country grasslands. Also, alpine glacier terrains alongside mammoths, giant ground sloths, and the first Native Americans – sound like an Ice Age movie scene.

The probable cause of its extinction might be partly the earlier extinction of some large herbivores. It may have preyed upon or scavenged and partly increased competition with the smaller grizzly bear that entered North America from Eurasia.

14. Megacerops

Last but not least, we come to the super-rhinos from about 35 million years ago named Megacerops. They were large-sized herbivore megafauna that could have survived by feeding on plants; their teeth were flat and low, similar to other animals, which helped grind vegetation. Prehistoric odd-toed ungulate, the megacerops belonged to an extinct group of rhinoceros-like browsers related to horses. It was endemic to North America.

Megacerops could reach around 8 feet tall at the shoulders and measure up to 5 m (16 ft) in length. The dorsal vertebrae above the shoulders had extra long spines to support the vast neck muscles needed to carry the heavy skull. It resembled a giant rhinoceros, possessing a Y-shaped horn-like protrusion on its nose with blunt ends – like a catapult to pick up and throw away incoming predators of smaller size. Wouldn’t like to be mistaken for one! The main reason for its extinction might be climate change and its accustomed food sources’ dwindling.

Conclusion

These were the most dreaded extinct animals listed down for you. Their extinction wasn’t an abrupt event. Throughout geological periods, due to the decreasing oxygen levels and shifting of climatic zones throughout the planet, megafauna has perished a great deal until today. Unlike in the case of a Titanoboa, present-day pollution and global warming might not support the survival of such giant species anymore for the rest of the animals. They are better off extinct and save us from nightmares!

Last Updated on June 28, 2023 by ritukhare