Imagine you are swimming on the beach, with a gentle breeze, hot summer, and closet companions. Suddenly your eyes grasp a towering 50 feet tall, 50-ton massive creature with pointy teeth with jaws big enough to fit your whole body.

Yikes! Before you run away, please read the article and comment on which prehistoric animal we are talking about.

Prehistoric animals are inferred as those frightening animals, giant in appearance, which once thrived and are extinct in the present context.  (Few animals brought back from Extinction)

Before the establishment of human-like creatures, they survived on the mother planet. The term Prehistoric is enough to understand that they existed before sighting humans. Several monstrous prehistoric animals survived in the past and have become extinct now. (Some of the prehistoric creatures are still around today)

It is believed that they survived between 200 million and 10,000 years ago. The Earth possessed the following monstrous animals, which were colossal. 

Table of Contents

1. Daeodon

Painting of Daeodon shoshonensis | Image Credit - Pinterest
Painting of Daeodon shoshonensis | Image Credit – Pinterest
Common nameDaeodon shoshonensis
Size1 ton in weight and 12 feet long
Existence periodRoughly 18-25 million years ago
Extinction reasonalteration in the dense forests and the expansive prairie

As referred to by the term ‘Dinohyus,’ meaning terrible pig during the prehistoric period, Daeodon shoshonensis existed on the Earth roughly 18-25 million years ago. 

The species were monstrous, furious, and omnivorous hogs. It was once abundant in the plains of North America. The external features of this species entail a meter-long skull with jaws filled with teeth. 

The teeth are established to have sound adaptation to the splintering of the bones of animals and the slicing fish. Daeodon is a massive hunter used to prey on and consume camels and horses.

They became extinct in the middle of the Miocene, probably a cause because of alteration in the dense forests and the expansive prairie. 

It is predicted to be the size of a modern hippopotamus. The facial features possess the odd nostrils facing towards the size of its head. Some scientists believe it is a scavenger; instead, the hunter fed the dead and the rotten carcasses. 

It is 1 ton in weight and 12 feet long in size. The crucial distinguishing characteristics of this species entail quadrupedal posture and the head of the bony arts.

2. Bone cruncher

Statue of Andrewsarchus mongoliensis
Statue of Andrewsarchus mongoliensis | Image – Dino Toy Blog
Common NameAndrewsarchus mongoliensis
Size800-1000 kilograms in weight
Existence periodBetween 45 and 36 million years ago
Extinction ReasonUnknown

Andrewsarchus mongoliensis was considered the largest carnivorous mammal during the middle Eocene epoch. It had occupied its range in the inner part of China and Mongolia.

It is studded with sharp teeth and covers the skull two and a half feet long. The external face of this animal seems petrifying. 

The species is supposed to have camels, pigs, and antelopes. Concerning the research, there is a lack of extensive findings regarding this species. 

Although there are no specific findings, scientists believe it fed on giant turtles and Brontotherium. It existed between 45 and 36 million years ago. To crush the bones, it bears the flat cheek teeth. 

It is astounding to depict that its cranium is roughly twice the length of the modern Alaskan brown bears. They are 800-1000 kilograms in weight which reveals that the food availability and the metabolic requirements hugely supported them.

3. Lemur

Rendered image of Archaeoindris
Rendered image of Archaeoindris | Image Credit – Additional Creatures Wiki
Common NameArchaeoindris sp
Size500 pounds in weight 
Existence periodBefore 350 BC
Extinction Reasonmassive hunting

For the first time in the prehistoric period, the lemur (Archaeoindris spp) survived in Madagascar during the Pleistocene age. 

It was likely of gorilla size. Its appearance was like that of the modern sloth which we visualize today. It possessed 500 pounds in weight, prolonged and gentle. There were the first human settlements in Madagascar. 

Once the last Ice age occurred, the human settlement had hunted this species, and massive hunting had unfortunately led it to extinction forever.

4. Woolly mammoth

Woolly Mammoth
Woolly Mammoth | Image Credit – Smithsonian
Common NameMammuthus primigenius
Size6 metric tons in weight 
Existence periodBetween 10,500 and 7600 years ago
Extinction ReasonMassive illegal poaching and hunting 

Woolly Mammoth (Mammuthus primigenius) is one of the extinct groups of elephants in the prehistoric period. They represented their habitat in all the continents except South America and Australia. 

In Siberia, the carcasses preservation of this species provided a significant clue regarding its structure and habitats.

Its ivory was used to export to many countries, such as China and Europe. Massive illegal poaching and hunting of this animal could have led this species to extinction in the past. 

Mammuthus primigenius thrived on isolated islands far away from human contact until 4000 years ago, according to the study published in Nature.

Inbreeding and genetic diversity loss have also summed up its life to extinction. Most of the mammoth’s population was double the size of the modern elephants. They harbor woolly, yellowish-brown undercoats with dark brown hair up to 50 cm.

The skull of Mammuthus primigenius seemed to be very high and possessed ears. Their ear was very beneficial because it supports adapting to the colder climate. Apart from this, the exposed small surface area was for the heat loss diminishing from their body. 

The tusks of the giant male mammoths reached up to 4 meters. Scientists estimated that the life of the woolly mammoth was likely the elephants of today. 

This species fed on the sedges and the grasses during the warmer season while shoots of the shrubs and the trees during winter. 

Because of glaciation as a cause of warming, this species underwent threats from natural causes. The woolly mammoth survived from the late Ionian of the Pleistocene to the early Holocene period. 

Containing the molar teeth of the woolly mammoths were supposed to support the effective processing of the grass quantity.

A fascinating fact about the woolly mammoth is that it would have a hump of the soft tissue above its shoulders intended to store fat for its survival during that period, which does not support the food resources and its availability for the long term. The cave hyenas fed mainly on their carcasses.  

5. Livyatan

Jaws of Leviathan | Video Credit – nature video
Common NameLeviathan melvillei
Size50 feet, and 50 tons of weight
Existence periodRoughly before 12-13 million years old
Extinction ReasonCooling events and reduction in food population

Leviathan melvillei is likely a killer whale having 50 feet and the size of 50 tons. It was leading to a top position in the Miocene food chain. Recently, the term ‘Leviathan’ has been eradicated since it had been already used to denote prehistoric elephants. 

This species is considered the deadliest prehistoric animal and survived roughly before 12-13 million years old, basically in the Miocene Epoch.

They used to exist in the southeastern Pacific Ocean along the Peru side. The body of this species was 13-16 meters long and more monstrous than the sperm whales. The skull was 3 meters. Leviathan Melvillei was the best swimmer in nature.

There seems to be a stark difference between its diet from that of the modern sperm whale. It used to prey on baleen whales and several other large marine animals. 

It’s an astounding fact of this species that it supports the body figure, which could fit the adult human body into its mouth. It critically reflects on how deadliest and most gigantic prehistoric animals were.

This whale has occasionally crossed the paths of the prehistoric shark Megalodon. It was discovered for the first time in Peru. 

Most scientists agree it was the ancestor of the modern sperm whale. Out of all prehistoric animals around the globe, the teeth of this species are regarded as the longest, excluding the tusk. It is used to tear the flesh into several pieces and consume seals, dolphins, and much more. 

Leviathan melvillei used to make up a large spermaceti organ, thereby serving as the ballast during deep diving. The other fundamental purpose of having the more significant spermaceti organ was in prey echolocation, intra-pod butting mating, and communication with other whales.

6. The giant short-faced bear

Arctodus simus
Arctodus simus | Image Credit – Paleo Media
Common NameArctodus simus
SizeCould go up to a height of 12-13 feet
Existence periodDuring the Pleistocene era
Extinction ReasonCompetition with the small grizzly bears for food

Inferred by the biological name Arctodus simus, it was one of the most monstrous and extinct prehistoric animals. The giant bear was thriving during the Pleistocene era in North America. This species is not under extensive research other than the other extinct prehistoric animals worldwide.

The most astounding fact this species reflected was it could run at 30-40 miles per hour, and for hunting the prey, it would reach its height of 12-13 feet. 

Still, the scientists cannot conclude the findings concerning its prey consumption. They preferred ranging from meat to vegetables. 

Broad research looks crucial to know whether it had active hunting or acted as a scavenger during its thriving period. This doubt is still existing in the present context.

7. Titanoboa

Titanoboa cerrejonensis
Image Credit – Art station
Common NameTitanoboa cerrejonensis
Size13 m long, possessing 1100 kg weight
Existence period58 to 60 million years ago
Extinction ReasonClimate change

It’s pretty blatant that most animals could not prey upon the crocodiles. But the pre-historical record revealed the existence of the giant Titanoboa cerrejonensis, which would prey on the crocodiles.

Its external body was 13 m long and 1100 kg in weight.  The thick giant Titanoboa cerrejonensis was like an anaconda. Its primary habitat is beneath the river or lake surface in Columbia.

This giant creature was supposed to have occurred 58 to 60 million years ago. The primary technique of this massive creature to capture the prey is seizing the prey which comes nearby it and dragging them underwater. 

It’s a petrifying prey attacking Titanoboa cerrejonensis where it entwines the prey before it causes constriction to the prey and ultimately results in the prey’s death.

8. Devil frogs

The biggest frog that ever lived | Image Credit – PBS Eons
Common NameBeelzebufo ampinga
Sizelength of 40 cm and weighs 4 kg
Existence periodAround 70 million years ago
Extinction ReasonHuge space rock clobbered Earth

It was an amphibian that existed in Madagascar around 70 million years ago. The species is so giant that it would dwarf the largest frogs thriving today. 

The species harbors a length of 40 cm and weighs 4 kg. It had broken the record of the largest amphibian ever existing in prehistory among other animals.

This monstrous species was very aggressive and would get hidden in the lush foliage intended to target its prey, such as giant lizards, insects, and young dinosaurs. The enormous jaws of Beelzebufo ampinga would grab the prey quickly upon their encounter.

9. Titanotylopus 

Size Comparison of Gigantocamelus spatulas with humans | Image Credit – Reigarw Comparisons
Common NameGigantocamelus spatulas 
Size3.7 m, and 300 cm in height
Existence periodPleistocene era
Extinction ReasonFood scarcity

Titanotylopus was formerly known as Gigantocamelus spatulus, which infers the giant camel during the prehistoric period. 

During the Pleistocene era, it existed as a huge camel. Its natural geographic range entails Eurasia and North America. It used to have an unusual brain.

The flat feet adapted naturally in such a way so that they could navigate the rough terrain. This camel was supposed to have originated in North America. Later on, with time passing, it spread in central Asia and the middle east after a long journey of a million years.

10. Indricotherium

Paraceratherium sp
Paraceratherium-sp chasing other creatures | Source
Common NameParaceratherium sp
SizeApproximately 20 tons’ body weight, 40 feet long
Existence periodAround 10 million years ago
Extinction ReasonUnknown

Indricotherium (Paraceratherium sp), meaning “Indric beast,” is regarded as one of the enormous terrestrial herbivores all across the globe in the animal kingdom’s history. 

It was once very abundant in the central and eastern parts of Eurasia. Its body size is supposed to be the size of the giant sauropod dinosaurs.

Around 10 million years ago, it existed on Earth. Some paleontologists and scientists reveal it was equal to the modern one-ton rhinos since Indricotherium bears 20 tons’ body weight. 

The primary characteristic of this species is it possesses a longer neck, and slender legs have three-toed feet. During the Oligocene period, it survived roughly 33 to 23 million years ago. It was a hornless rhino species. 

Having a size of approximately 20 tons, it was 40 feet long. The upper lip of this mammal is fascinating. The historical record by the scientists lamented that the upper lip of those species permits them to grab the trees’ leaves and branches.

11. G. blacki

Gigantopithecus Blacki
Great ape Gigantopithecus Blacki | Image Credit – Reddit
Common NameGigantopithecus blacki
Size3 m tall, 500 kg in weight
Existence period300,000 to 1 million years ago
Extinction ReasonClimate change

Gigantopithecus blacki was an enormous ape recorded in China, India, and Vietnam in the prehistoric period. This species survived 300,000 to 1 million years ago. This species stood at 3 m tall and bore over 500 kilograms in weight.

The primary specialty of this species is its enormous bulk and brute strength, primarily letting them be far from predators. Since it lives in the joint habitat of tigers, leopards, and black bears, these giant creatures were terrified of Gigantopithecus blacki because of its enormous bulk.

It was an herbivore in nature. Since it’s one of the giant ape species, it possessed muscular jaws aimed to chew the tough grasses basically in the forests of southeast Asia. Because of climate change’s effects, it became extinct over several centuries.

12. Supercroc

Sarcosuchus imperator
Skull of Sarcosuchus in a museum | Image Credit – Thoughtco.
Common NameSarcosuchus imperator
Size10 tons of  weight
Existence period110 million years ago
Extinction ReasonLack of food and habitat

This crocodile species was the significant habitat of sub-Saharan Africa, which survived 110 million years ago. It bears stout with pointed back teeth along with giant jaws. The jaws were more extensive than those of humans.

Experts believe that once it seizes its victim or the prey, the prey could never escape since this species would drag the prey back into the water and make them drown. Once the prey got drowned, it consumed it heavily.

The crocodile was 10 tons in weight. There is a unique mechanism of targeting the prey and consuming revealed by scientists and wildlife researchers.

13. Utahraptor

Common NameUtahraptor ostrommaysorum
Size1500 pounds and 20 feet 
Existence period125 to 130 million years ago
Extinction ReasonNatural death

It is the monstrous prehistoric raptor dinosaur throughout the globe. It was the older Raptor who lived during the historical period. 

It comprises 1500 pounds and is 20 feet. It was supposed to be extinct 125 to 130 million years ago. It belonged to the early phase of the Cretaceous era. It used to cover its abundance in North America in prehistoric times.

The gigantic creature used to slash and gut the prey. The most astounding fact about Utahraptor, besides having excellent predators, was that they had the best capability to hear the low-frequency sounds. 

Since they have excellent hearing skills, targeting and capturing their prey in large packs would be convenient. Because of its gigantic body size, it would not run speedily.

The body size was unfortunate for them to run faster than their prey. The fundamental habitat of Raptor was floodplains and the woodlands in most semi-arid regions. 

The species were oviparous. The communication skills of the Utah-raptor are considered unique since it is used to communicate through gestures and plumage display. The paleontologists estimate they were agile, basically targeting and hunting for their prey.

Their death was supposed to be the natural cause. It used to cover the extensive range of its habitats, and the skulls and the body figure are enough for us to understand how monstrous this species was during the historical period.

Concluding Remarks

Definitely, someone gets frightened when there is the presence of a monstrous animal around us. Despite the terrified physical appearance of an animal, every species has the full right to thrive in its natural surroundings. Because of the aforementioned anthropogenic-induced interventions, they have undergone extinction except for some of the natural causes. 

Besides you, some may prefer to know about the prehistoric animals that have existed at one time in global history. Let’s share the information on the monstrous prehistoric animals and expand the knowledge widely.

(Last Updated on April 21, 2022 by Sadrish Dabadi)

Kalpana Ghimire holds a post-graduate degree in Environmental Science from Nepal. She possesses numerous research experiences working in water pollution, community forestry, environment conservation status, and wildlife ecology. She was an internee in the Department of Environment (EIA monitoring and auditing section) under the Government of Nepal. Kalpana Ghimire is an avid traveler, an enthusiastic wildlife researcher, and has a huge passion for working in the environment sector. She loves far traveling to the natural areas, conducting field wildlife research and reading the novels.