1. Pelagornis Sandersi
This is what scientists believe to be the largest flying bird that ever existed. It has a wingspan of up to 24 feet. These birds were most commonly found over the ocean. They got around by jumping off cliffs and allowing the wind currents to take them and keep them in flight.
2. Euphoberia (Giant Centipede)
This creature is very similar to the modern centipede that wee see today. The only difference is that this creature is over three feet long. The centipedes of today prey on birds, bats, and snakes. While it is not known what the Euphoberia eats, however, considering its size, there are many things that these creatures would have been capable of feasting on.
This creature lived around 9 million years ago around Asia. This creature is what scientists believe to be the largest ape on Earth. They could grow up to 10 feet tall and they could weigh up to 1,200 pounds. They are believed to have walked on all fours the way that modern gorillas or chimpanzees do. Some scientists believe that they walked with a bipedal or like a human locomotion. There is not actual proof of who is correct. The way that the animal’s teeth and jaws are constructed, they were able to chew very tough and fibrous foods by crushing, cutting, or grinding it down. These creatures were likely not a creature that you would want to happen upon in the jungle.
Scientists believe that these animals existed between 36 and 45 million years ago. They were a giant carnivorous mammal. Based on a skull and several of the animal’s bones that were found, scientists believe that this animal weighed up to 4,000 pounds. They also believe that this animal was the largest land-dwelling mammal ever. Scientists don’t really understand the behavioral patterns of the animal, however, they believe that they might have been omnivorous or scavengers.
This is one of the frightening creatures that ever existed. Its name means, breathing scorpion. It is believed that this creature lived between 330 and 345 million years ago. Fossils from this animal were found in Scotland, and scientists believe that it could grow up to 30 inches long. Fortunately, this creature wasn’t very dangerous to humans. Scientists believe that it fed mainly on tetrapods and arthropods.
Megalania is a giant lizard that lived around 30,000 years ago. Scientists believe that is native to Southern Australia. This means that the first settlers in Australia may have had a few run-ins with this lizard. If someone did, it could have been extremely terrifying, as they likely grew to be up to 25 feet long. If this is correct, the Megalania would be the largest terrestrial lizard to ever have existed.
This prehistorical creature lived between 250 and 310 years ago. This creature resembles the shark, but it has a terrifying mouth. Its teeth were arranged in spiral clusters, called tooth whorls. They can grow up to 13 feet long, making them a creature that you would never have wanted to run into while scuba diving. The very appearance of the shark alone is enough to make your drop from a heart attack.
This prehistoric creature was very strange looking. It was a pig-like mammal and have a major appetite for meat. Even though it was standing on all fours, it was still as tall as a man. It was one of the most monstrous looking creatures to ever have existed. Scientists believe that this animal was also cannibalistic. If they could not find prey, they would prey on each other. This makes them very unique and even scarier.
This sea creature was native to the Cambrian seas. Its name means abnormal shrimp, and is was closely related to ancestral arthropods. According to scientists, it was a predator that fed mostly on hard-bodied sea creatures. They were easily able to spot their prey because they had 30,000 lenses in each eye. They had the most advanced eyesight of any species of creature to ever exist.
It is believed that this creature lived during the Carboniferous period. It resembles the dragonflies that we see today, however, it was quite a bit larger. It has a wingspan of up to 26 inches. It is considered one of the largest species of flying insects to ever live on Earth. If you were to see this creature today, you wouldn’t need to worry. It had a diet that consisted of small amphibians and other insects.
This was a relatively frightening looking creature. It resembled a spider and had a tail that resembled scorpions. For many years, scientists believed that this was the prehistoric ancestor of the modern spider. When scientists discovered the fossil, they started to rethink their original ideas. They believe that while this creature didn’t spin webs, it may have used silk to wrap its eggs until they hatch. They also believe that this creature lived underground and burrowed walls to build their homes.
This is a terrifying creature that was related to the modern crocodile and alligator. They are believed to have lived between 73 and 80 million years ago. While the creature looked just like today’s species, they were much larger. They could grow up to 40 feet long and over 1,000 pounds. What made the creature even more terrifying is that it had very large, sharp teeth, and it was capable fo killing and eating sea turtles, and even large dinosaurs.
This creature lived during the late Devonian period, between 360 and 380 million years ago. It was a hypercarnivorous fish. What made this creature so terrifying is its amazing size. It could grow to be 33 feet and could weigh close to 4 tons. It was a heavily armored fish, and it was a very strong swimmer. At the time, it was a very fierce predator. Just the size of its mouth alone made it able to suck its predators in, whole.
This creature was bigger than the T-Rex, the most well known and feared dinosaur. It was a carnivorous dinosaur, and it could grow to be 59 feet tall and weighed up to 10 tons. This creature ate fish, turtles, and other dinosaurs. If this creature were still alive today, chances are, the human population would have become extinct.
This creature lived in North and South America around 2.5 million years ago. It lived during the Pleistocene epoch period. It is the best-known example of the saber-toothed cat. It had extremely large and sharp upper canines, which made it very easy to catch and eat its prey. It had very well developed forelimbs and could weigh as much as 900 pounds. It is the last thing that you would want to happen upon if you were walking through a field.
This creature was one of the largest creatures ever to fly, with a wingspan of up to 40 feet. The size and mass of the birds were extremely huge, and they had huge breasts. There was no creature that shared a similar size or body plan back then and there is still no other creature that shares it today.
Scientists decided on the name, Hallucigenia because the creatures are so strange and they look like something from a dream, almost like a hallucination. It was a worm-like creature, who was around 2 inches long. Its head did not have any sensory organs, such as a nose or eyes. It has testicles on each side of its body and three sets of tentacles behind the testicles.
18. Short-Faced Bear
This bear could be found in North America during the Pleistocene period around 11,000 years ago. He is the most recent creature on this list. His size showed that he truly was prehistoric. When standing on his hind legs, he could be 12 feet tall. His arms could reach out to 14 vertical feet. The weight estimation of this bear is over 3,000 pounds.
This horrifying creature lived between 58 and 60 million years ago. It is the longest, largest, and heaviest snake to ever be discovered. Scientists believe that this snake could grow up to 42 feet and weigh over 2,500 pounds. It had the ability to crush and devour giant crocodiles and turtles. It lived in South America, and if it still lived today, South America would not be a heavily populated area.