Buzz
Prehistoric creatures took on all sorts of extraordinary forms over time, driven by factors such as changes in ecosystems, fluctuating food sources, and the emergence of new opportunities following the extinction of predators or rivals.
At times, however, Mother Nature seemed to get a little too creative, producing truly bizarre creatures that even the most dedicated scientists, who specialize in unearthing the strange and ancient, find baffling.
10. The Dinosaur-Bird with a Tooth-Like Beak
Birds are, in essence, modern-day dinosaurs. However, the shift from one to the other was so gradual and fragmented that figuring out the exact transition is quite a complex puzzle.
A fascinating discovery from this perplexing phase of evolutionary history is the Ichthyornis dispar, a creature that serves as a “stem bird” bridging the gap between dinosaurs and birds in a rather peculiar way.
This creature lived in Kansas 100 million years ago, during a time when the region was covered by an inland sea. Despite its long beak, I. dispar still retained its dinosaur-like teeth.
Combining the best features of both worlds, it terrorized the ancient seas, snatching fish with its bird-like beak and then pulverizing them with its powerful, muscular dinosaur jaw into a paste.
What’s inside its head is equally crucial. The I. dispar boasted a surprisingly large brain to match its imposing beak. This contradicts theories that suggest jaw muscles should shrink as skulls (and brains) increase in size.
It’s no surprise that the intelligent and formidable I. dispar and its kin had a promising future.
9. The 1,000-Kilogram (2,200 lb) Guinea Pig That Impaled Enemies With Its Enormous Tusks
Three million years ago, prehistoric rodents were built with tremendous strength. The Uruguayan Josephoartigasia monesi was the mightiest of them all, with a massive 1,000-kilogram (2,200 lb) frame that could stand shoulder to shoulder with a bull.
Among the most striking features of rodents are their oversized front teeth. The mighty guinea pig J. monesi also reigned supreme in the dental world, sporting 30-centimeter (12-inch) incisors that were more tusk-like than typical rodent teeth.
Seeing these enormous teeth wasn’t enough for scientists, who were curious about their functionality. Through CT scans, virtual models, and computer simulations, they reconstructed J. monesi’s bite and discovered it could deliver a force comparable to a tiger’s—despite its teeth being able to withstand three times that force.
This was likely because J. monesi didn’t just bite. It likely used its tusk-like incisors to stab anything that annoyed it. The creature also employed its teeth to root through the ground, uncovering food much like an elephant would. Quite impressive for a distant relative of the guinea pig.
8. The Incredible Pig-Nosed Turtle
Turtles are among the most ancient creatures on Earth, having been around for over 250 million years. Despite some disagreements on their size, nature has generally stuck with a conservative approach to turtle design throughout prehistory.
The exception to this trend?
A small evolutionary anomaly 76 million years ago led to the creation of the quirky, pig-nosed Arvinachelys goldeni.
This turtle lived in Utah during a time when North America was a large island known as Laramidia. Utah’s landscape was vastly different in the Cretaceous period, with deserts replaced by hot, humid swamps that expanded into floodplains, bayous, and rivers perfect for the pig-nosed turtle to explore.
A. goldeni adds another layer to the evolutionary mystery of Laramidia. Creatures from the northern and southern parts of the landmass looked strikingly different from each other, presenting an unexpected level of differentiation without any obvious barriers separating the two groups. The arrival of the pig-nosed turtle didn’t help solve this puzzle.
7. The Pug-Faced Mega-Hyena
Pachycrocuta brevirostris, also known as the “short-faced hyena,” earned its name due to its pug-like, snub-nosed face. However, don't be deceived by its comical appearance. P. brevirostris was one of the most fearsome hyenas to ever roam the Earth.
This hyena had the mass of a lion, yet its body was no taller than today’s spotted hyena. P. brevirostris had a dense, muscular frame, short limbs, and a powerful jaw designed for scavenging dominance.
Its low and hunched posture gave it incredible leverage, allowing it to rip massive chunks of meat from large carcasses. Afterward, P. brevirostris would drag its prize away to enjoy it in safety before launching its next hit-and-run attack.
P. brevirostris muscled its way into the evolutionary spotlight around three million years ago in Africa and Asia. It then made its way into Europe approximately one million years later.
Unfortunately, this coincided with similar migrations by our ancestors. Evidence suggests that early humans and hyenas shared the same territories. This was less than ideal for us, as shown by the mutilated Homo erectus remains discovered at the Dragon Bone Hill site in China.
6. The Dolphin That Thought It Was A Swordfish
The oceans have seen many strange creatures rise and fall with the changing temperatures. One of the most bizarre was a dolphin that used a swordlike nose to strike its prey—much like a swordfish.
The longest-snouted mammal in history, Zarhachis flagellator, made its debut 20 million years ago during the Neogene Period. This creature boasted a snout five times the length of its skull—over 1 meter (3 ft) long—that swept through the water as it hunted for food. Once it found its prey, Z. flagellator would strike with its weaponized snout, knocking its victim senseless.
Scientists concluded this by studying the structure of Z. flagellator's snout to gauge the forces it could endure. They also compared its anatomy with similar prehistoric dolphins and modern marlins.
However, the changing climate eventually led to the extinction of Z. flagellator at the start of the Pliocene Epoch. A harsh glaciation period disrupted the creature's environment and food sources, leading to the extinction of these long-snouted animals around 2.5 million years ago.
5. The Cold-Blooded Goat
Myotragus balearicus, a tiny 46-centimeter-tall (18 in) dwarf goat from the Balearic Islands, managed to survive for millions of years by adopting a cold-blooded strategy straight out of the reptilian playbook.
The ancient bones of this goat astonished scientists, who were surprised to find tree-like growth rings within. Warm-blooded animals don't have such features since their bones continuously grow, but cold-blooded creatures experience spurts of bone growth when resources are available.
The harsh, barren environment of Majorca left the Balearic goat with few resources, forcing it to shrink and adopt some reptilian traits. This allowed it to bask in the sun all day without the constant need to search for food.
However, the goat's reduced size and slow metabolism had a downside: M. balearicus couldn't defend itself or run from predators. Fortunately, the island had no predators to worry about.
This small, defenseless, nonathletic goat thrived in its Mediterranean haven for 5.2 million years—double the typical lifespan of mammal species. M. balearicus was only wiped out 3,000 years ago with the arrival of humans.
4. The Crocodilian That Walked Upright
The world of dinosaurs is filled with unanswered questions. One mystery revolves around how dinosaurs managed to survive alongside their reptilian rivals, the rauisuchians—proto-crocodilians that predated them.
While crocodiles have splayed legs, rauisuchians—ancestors of crocodiles—had a more vertical leg posture, holding their limbs straight beneath their bodies. This upright stance allowed for more efficient and faster movement when traveling on four legs, a feature they frequently employed.
Initially, it seemed that dinosaurs had the advantage in outlasting their Triassic relatives, thanks to bipedalism—a faster, more efficient way to move. However, research has shown that at least some rauisuchians also walked on two legs. One example is Poposaurus gracilis, a creature that blurred the lines between dinosaurs and their crocodilian ancestors.
The 225-million-year-old P. gracilis stretched to about 4 meters (13 ft) in length and featured backward-curved teeth perfect for slicing through its prey. Despite its small arms, the creature compensated with a long, pointed tail, enabling it to walk and run upright like its hardier dinosaur relatives.
With P. gracilis, the enigma of why dinosaurs ultimately triumphed in the evolutionary race is reignited.
3. The Anchovy That Wore Sabers
Some fossils spend years tucked away in museums before their true significance is uncovered. Two such fossils sat for 20 years, only recently revealing that ancient anchovies were much fiercer than their modern-day, plankton-feeding cousins. While today's anchovies grow to about 15 centimeters (6 in) and feed on plankton, the prehistoric Monosmilus chureloides reached lengths of 1 meter (3 ft) and feasted on other fish.
It also sported a sabertooth—one large fang protruding from its upper jaw to accompany a row of sharp teeth on the lower jaw. That's right, M. chureloides was a predatory anchovy that skewered its prey.
The 45-million-year-old M. chureloides comes from the Paleogene period, when many fish species unexpectedly turned into deadly predators. The opportunity for ferocious fish arose after the extinction of larger sea monsters, triggered by the asteroid impact that wiped out the dinosaurs 66 million years ago.
Like its fellow fish species, the ancient anchovy from the Eocene Epoch evolved into a ruthless hunter, filling the gap and preying on smaller fish.
2. The Armored Basking Fish
The armored fish Titanichthys was among the largest marine creatures of the Devonian Period, over 380 million years ago. Reaching lengths of over 5 meters (16 ft), Titanichthys had a jaw spanning 1 meter (3 ft). However, this massive jaw was surprisingly toothless and lacked a cutting edge.
If its jaw wasn’t meant for combat or tearing apart its prey, what was its purpose? As it turns out, this imposing fish wasn’t all that terrifying. Instead, it made its living as a 'suspension feeder,' much like the modern basking shark.
Despite its formidable size, Titanichthys used a leisurely yet effective feeding technique called 'continuous ram feeding.' It simply drifted through the waters with its mouth wide open, collecting the tiny organisms that filled the ancient sea, now part of the Moroccan Sahara Desert.
Titanichthys set a trend as the earliest known creature to 'bask,' predating other famous basking animals, like baleen whales, by an astonishing 350 million years.
1. The Ferociously Vegetarian Cave Bear
The European cave bear, named for its penchant for caves, could weigh as much as 500 kilograms (1,100 lb), rivaling the largest bears alive today. However, unlike the omnivorous, picnic-ruining bears we know, this ancient species was 'strictly herbivorous.'
These bears roamed across Europe and Asia from 300,000 to 25,000 years ago, going extinct around the time of the Last Glacial Maximum. Despite living in dry, cold conditions, Ursus spelaeus thrived on a plant-based diet, finding enough vegetation to sustain its large, -meter-long (11.5 ft) body.
How did scientists determine this?
They studied the bones of six cave bears found at three Romanian cave sites, some dating back nearly 50,000 years. By examining the fossilized collagen in the bones and comparing it to collagen from carnivores, herbivores, and other cave bears across Europe, they confirmed the bear's strictly vegetarian diet.
By examining the nitrogen composition in the amino acids of the collagen, researchers concluded that U. spelaeus exclusively followed a vegetarian diet.
