We have already published a few posts about dinosaurs, the largest creatures that have ever roamed on Earth but in fact, in the prehistoric era, almost all animals as well as plants were much bigger than their modern counterparts. From an elephant-size sloth to a car-size armadillo, check out these 25 giant prehistoric ancestors that would make their contemporary relatives look like dwarfs.
These days, the polar bear and the Kodiak bear are considered the largest species of bear, both of them weighing as much as 1500 pounds (680 kg), which is an impressive size but compared to the short-faced bear, these are still lightweight. This extinct bear inhabited North America during the Pleistocene epoch until 11,000 years ago and was – when standing on its hind legs – up to 12 feet (3.7 m) tall. Moreover its estimated to have weighed over 3,000 pounds (1360 kg).
While today, the largest eagle species of eagles such as the Philippine, harpy or wedge-tailed eagle usually weigh up to 15 pounds (6.7 kg) and have wingspans of up to 7 feet (about 213 cm), the Haast´s eagle was considerably larger. Once native to New Zealand where it became extinct some 600 years ago, this raptor could weigh more than 35 pounds (16 kg), and though it had a relatively short wingspan for their size, it was still much longer than the one of the modern eagles.
We currently know 5 different species of tapir that range in size from 330 to 700 pounds (150-300 kg) but from the Middle Pleistocene to about 4,000 years ago, there was a creature called megatapirus that was bigger, considerably heavier and more massive. Living in today’s China and Vietnam, the extinct prehistoric tapir may have weighed up to 1,100 pounds (500 kg).
Endemic to South America, Megatherium was a genus of elephant-sized ground sloths. Living from the late Pliocene to the end of the Pleistocene, it was one of the largest land mammals known, weighing up to 4 tons and measuring up to 20 feet (6 m) in length. Scientists suggest that Megatherium was capable of bipedal locomotion and had a long tongue used for putting leaves into its mouth.
There are three known species of wombats today, ranging in weight from 44 to 77 pounds (20 – 35 kg) and usually reaching a length of less than 40 inches (1 m). It’s hard to believe that these cute marsupials native to Australia evolved from a creature the size of a rhinoceros. Diprotodon, a member of a group of unusual species collectively called the “Australian megafauna” and the largest marsupial ever, was up to 10 feet (over 3 m) long and weighed over 6,100 pounds (almost 2800 kg).
If you think modern sharks are large and terrifying, you probably haven´t heard of megalodon. Meaning “big tooth”, Megalodon is an extinct species of giant shark that lived approximately 28 to 1.5 million years ago. Thanks to its incredible length of up to 60 feet (over 18 m), it’s considered one of the largest and most powerful predators ever. Distributed worldwide, Megalodon basically looked like a much larger and formidable version of the great white shark.
These days, the Chinese giant salamander with a length of up to 6 feet (180 cm) is the largest amphibian in the world. While it may sound impressive by modern standards, compared to the size of prionosuchus, it’s a totally negligible number. Living in the Middle Permian (270 million years ago) in today Brazil, this crocodile-like creature reached an estimated length of 30 feet (9 m). It had an elongated snout, sharp teeth, short legs, and a tail adapted for swimming.
Even insect species have their giant prehistoric relatives. Meganeura was a genus of extinct insects from the Carboniferous period which are related to present-day dragonflies. With wingspans of up to 26 inches (almost 70 cm), it is one of the largest known flying insect species that ever lived on Earth. Meganeura was a predator with its diet consisted mainly of other insects and small amphibians.
The pink fairy armadillo, the smallest living species of armadillo, weighing about 4.2 oz (120 g) and measuring about 4 inches (10 cm), comes from the glyptodont, a giant armadillo that lived during the Pleistocene epoch. Reaching well over 10 feet (3 m) in length, and a weighing up to 2 tons, this prehistoric armored herbivore was the size of a small car.
Disturbingly similar to the fictional giant ape King Kong, gigantopithecus was a real animal living between 9 million to 100,000 years ago in today’s Asia. Standing up to 10 feet (3m) tall and weighing up to 1,200 pounds (540 kg), it was the largest ape on Earth. The creature is believed to have walked on all fours like modern gorillas and chimpanzees; however, a minority opinion favors bipedal, human-like locomotion.
Once common throughout Europe and northern Asia, the woolly rhinoceros was a large and stocky animal typically up to 13 feet (4 m) in length, with an estimated weight of up to 7,000 pounds (almost 3,200 kg). A member of the Pleistocene megafauna, it survived the last glacial period.
With a weight of up to 320 pounds (145 kg) and a height of up to 9 feet (2.8 m), the modern ostrich is the largest and heaviest bird in the world. But compared to Phorusrhacid (colloquially known as the terror bird), the ostrich is a lightweight. These prehistoric carnivores were slightly taller but much more robust and massive than today’s ostriches and weighed about half a ton. But despite their enormous body mass, they might have been able to run as fast as a cheetah.
The feared Komodo dragon, world´s largest monitor lizard, can be up to 10 feet (3 m) long and weight as much as 150 pounds (70 kg). However, Megalania, its Australian ancestor, was even bigger. This giant lizard, that became extinct as recently as just about 30,000 years ago, could have been about 25 feet (7.6 m) long with a weight of well over 1,000 pounds (450 kg) which would make Megalania the largest terrestrial lizard known to have ever existed.
We already talked about the woolly rhino but in fact, modern rhinos have one more ancient ancestor – paraceratherium. Living in the Oligocene epoch, this hornless rhinoceros is the largest terrestrial mammal that has ever existed. Weighing as much as incredible 20 tons and reaching a length of 30 feet (9 m), this giant herbivore occupied an area of today Europe and Asia.
Despite their small size, modern scorpions are dangerous and formidable creatures feared by many people. Therefore, meeting their 30 inches (76 m) long prehistoric relative Pulmonoscorpius would be a real nightmare. Meaning „breathing scorpion“, Pulmonoscorpius is a giant species of extinct scorpion that lived some 345 – 330 million years ago. It was a terrestrial creature feeding probably on small arthropods and tetrapods.
After the tiger, African lion is the world´s second largest cat with males sometimes exceeding 550 pounds (250 kg) in weight but as recently as 11,000 years ago, there was a lion in North America that had even more impressive size. Many well-preserved fossils of the species were found, enabling us to determine its real proportions. The animal was up to over 8 feet (2.5 m) long and could weigh over 770 pounds (350 kg).
These days, capybara, the largest living rodent, can weigh as much as 146 pounds (66 kg) which sounds like a lot but compared to the size of Josephoartigasia monesi, an extinct species of South American rodent, it is absolutely nothing. Living 4 to 2 million years ago, monesi , sometimes also called the giant pacarana, after its closest living relative – the pacarana, may have weighed a ton – a lot more than any modern rodent.
Even today, crocodiles are perceived as huge and fearsome animals. They are considered direct descendants of dinosaurs but in fact, there were crocodilian species that actually hunted dinosaurs. Living 80 to 73 million years ago, Deinosuchus was one of them. Reaching up to 40 feet (over 12 meters) in length and 10 tons in weight, Deinosuchus had large, sharp teeth capable of killing and eating sea turtles, fish and even large dinosaurs.
Talking about ancient turtles, we should also mention the largest turtle that has ever existed. Archelon, giant a marine turtle, whose closest living relative in the present day is the leatherback sea turtle, was more than 4 meters (13 ft) long, and almost 5 meters (16 ft) wide. With fossils found mainly in the northern part of the U.S., the weight of the turtle is estimated at more than 2200 kg (4,850 lb).
Although looking more like a giant rat, Deinogalerix was a relative of modern hedgehogs. But while hedgehogs are usually just about 8 inches (20 cm) long, this animal was three times larger with just its skull being the size of a modern hedgehog. Paleontological research suggests that this species might have been endemic to a confined area today known as the Gargano Peninsula, Italy.
These days, rabbits are often kept as pets for their fluffy hair, cute look and small size but even this little mammal evolved from a much larger and considerably less adorable creature. Nuralagus rex, a giant ancient rabbit weighing over 50 pounds (23 kg), is something that children probably wouldn’t want to share their bedroom with. Unlike modern rabbits, this one had small eyes, ears and skull but enormously large and massive body and legs.
There has been a constant dispute about what the world´s largest living snake is with several species claiming the title but there is absolutely no doubt about what snake is the largest and heaviest ever. It is titanoboa, a gargantuan beast that lived some 60–58 million years ago. Researchers estimate that the largest individuals could have a total length of around 42 feet (13 m) and weighed about 2,500 pounds (over 1,100 kg). No wonder its diet usually consisted of giant crocodiles and turtles.
Some modern owls are quite large birds – by our standards – but they all fly. In the Late Pleistocene period though, there was an owl too large to fly. Measuring almost 4 feet (1.1 m) in height and weighing well over 20 pounds (9 kg), ornimegalonyx is probably the largest and heaviest owl that has ever lived on Earth. Native to today Cuba, it was able to hunt a prey of 80 pounds (36 kg).
Woolly mammoth is not the only ancestor of present day elephants. If we go further back in the prehistoric era, we will come across deinotherium, a large elephant-like creature with strange short tusks growing from its lower jaw. According to a size of a skull found in Germany in 1836, we know that these animals greatly exceeded modern elephants in size. The most typical feature of deinotherium was a pair of curious tusks but their purpose is still unclear.
After elephant and rhino, hippopotamus, weighing up to 4,000 pounds (1,800 kg,) is the third largest land mammal. However, some 5 – 2 million years ago, there was a prehistoric hippo more than twice as big. With a length of 4.3 meters (14 ft), shoulder height of 2.1 meters (6.9 ft) and a weight of 3,900 kilograms (8,600 lb), Hippopotamus gorgops spent most of the time in the water that helped him to lift the huge body mass.