Mysterious fossils science still can't explain

Fossils capture the imagination, giving us a glimpse into the past. While many of the more mysterious fossils have been explained away by now, a few remain a total enigma, with theories ranging from giants, missing link humans, sea-floor cacti, and even fossils from outer-space. Let's dive into fossils that scientists just can't explain.

ALH84001 (the Martian bacterial fossil)

Countless science fiction stories revolve around life on Mars, and more than a few pseudo-scientists have found "proof" of life in odd Martian rock formations and camera glitches. But scientists take possible life on Mars seriously, and actually might have proof in the mysterious meteorite known as ALH84001.

The little meteor fell to Earth in 1984 and seemed like an interesting, albeit normal, meteor sample. With more study, scientists came to a shocking conclusion. The meteor was from Mars and was 4.1 billion years old. It was blown off the planet during a collision and traveled space since then, finally coming down to Earth. Even more shockingly, it had what looked like features of fossilized bacteria in it. Overnight, ALH84001 became the most famous meteor on Earth.

Since then, scientists have debated the nature of the rock. Sure, it looks like there are bacteria embedded in it, but further study has proven inconclusive. It could just be remnants of mineral structures found on Mars all those years ago, or a fluke of geologic formation. What makes ALH84001 so amazing is that, even after thirty years of study, it's still a mystery. Scientists still take it very seriously, with groups even proposing that ALH84001 provides evidence that the Moon and other worlds could be littered with fossils knocked away from Earth by asteroid collisions. Possibly, the planets are constantly trading rocks through this mechanism, and maybe even trading life as well.

Homo naledi

Since the discovery of early hominid fossils, most researchers focused in small geographic areas where they felt certain they'd find fossils of our ancestors. All that changed in 2015, when researchers in South Africa found hominid fossils that didn't relate to any of the known hominid fossil families. Named Homo naledi, the fossils were from a new family of human predecessors.

Homo naledi fossils occupy a weird place in the human family tree, falling between hominids and apes both structurally and behaviorally. This has led some researchers to propose that they're not truly hominids, but instead some sort of evolutionary middle child that defies classification. Oddly, the specimen was less than 350,000 years old, meaning it lived right before Homo sapiens appeared. Yet, their bodies are more similar to older hominid specimens. This would be like finding out that neanderthals were still alive somewhere in our world today. Homo naledi was that out of place.

More mysteries crop up when analyzing their behavior. All the fossils were found in a large burial hole, but it seems like the Homo naledi might have just dumped the bodies there without any ritual.

All this adds up to a puzzling picture, especially when you consider that this species might have survived up until the development of Homo sapiens. This means that our ancestors probably had contact with small-brained hominids, contrary to what was previously thought, forcing us to re-evaluate the timeline of human development. How Homo naledi developed at all, and whether our ancestors actually interacted with them, is still a mystery.

Tully Monster

Discovered in 1955 by collector Francis Tully, the first Tully Monster fossil completely defied explanation. Paleontologists eagerly attempted to place the fossil within well-known classifications, but nobody could figure out what the monster was actually related to.

Looking at reproductions of the monster show why it was so confusing. The main part of the creature had a body like a cuttlefish, with vertical fins sticking off the top. It had no bones in its body, but could keep a rigid shape like mollusks or worms do. Eye pods stuck out from the sides of the body. Most unusually, the monster had a long, segmented proboscis with a "head" on the end. Unlike the proboscis found on animals like butterflies, the Tully Monster's proboscis ended in a set of jaws with teeth. Adding it all up, the Tully Monster looked like something a child would draw.

When trying to set it into classification, researchers were completely stumped about where it fit. They thought it might be related to a worm, mollusk, arthropod, or a conodont. Unfortunately, all those classifications are unrelated to each other. Finally, some samples showed up with a rudimentary spinal cord, letting researchers know that they could at least classify it as an early vertebrate. Aside from that, the Tully Monster still remains a baffling evolutionary turn in our planet's history. Researchers are still trying to decide how it evolved and what place it held in the prehistoric ecosystem.

The dinosaur fossils found in the frozen Arctic

When we imagine dinosaurs, we usually picture them in warm, tropical climates, or in the warm oceans. Since most dinosaur fossils are discovered in these types of climates, that image makes sense. But recently, scientists have discovered a new species of dinosaur living in the most unlikely of places: Arctic Alaska.

The new dinosaurs have the fun name Ugrunaaluk kuukpikensis, and lived 70 million years ago in the frozen North. The discovery of these duck-billed dinosaurs have created countless questions, forcing paleontologists to completely rethink what they believe about dinosaurs. Since these giant lizards lived in polar climates, they must have created their own heat, totally changing the idea that dinosaurs were only cold-blooded creatures. Most likely, their blood systems were much more diverse than original thought.

But the biggest mystery is how these frigid dinosaurs made it up there in the first place, so far removed from the biggest populations of their scaly cousins. Something had to get them up there, and scientists are hard-pressed to figure out what made them migrate North. Whatever the case, these dinosaurs lived a rough life, combating months of snow and darkness since they lived in the Arctic year-round. With the mystery of their migration, blood chemistry, and the other gnawing question of what exactly they ate in the frozen tundra, Alaska is rapidly becoming the last frontier of paleontology, one of the last places where mysteries about these scaly creatures still abound.

Klerksdorp Spheres

The Klerksdorp Spheres were first discovered in Ottosdal, South Africa, during mineral deposit excavations. The spheres became an intense curiosity among the miners and geologists as more cropped up during the dig. As the name suggests, they're spherical in shape and made out of an extremely hard mixture of metals.

Most of the spheres have a groove running around their equator. These spheres' grooves date back to 3 million BC, which quickly led to conspiracy theories about ancient aliens or highly advanced prehistoric civilizations. The spheres just seemed too perfect for any natural process. Ancient astronaut theorists quickly latched on to the story and speculated that these were out-of-place artifacts left by aliens.

Of course, party-pooper geologists were quick to shoot down the idea. They pointed out that the fossils could have occurred due to natural, volcanic activity. Certain types of volcanic metals are apt to form spherical shapes, and weather could have created the equatorial groves. Geologists point out that spherical rocks are not uncommon, but conspiracy theorists hold onto the idea that the spheres are part of the fossil record of ancient alien contact with the Earth.

Honestly, neither group has an airtight theory about the spheres' origin. Geologists have remained skeptical, but have not yet come up with a solid explanation, and ancient alien conspiracists still cannot explain why aliens would come down to Earth just to litter metal spheres all over South Africa. That's an awful long route to travel just to relieve boredom.


Amateur paleontologists are often the ones digging up mysterious and surprising fossils. Recently, Ron Fine and his team found an incredibly unusual fossil just outside of Covington, Kentucky. Finding various chunks with plant-like patterns during a dig, Fine realized that they had discovered a broken-up fossil. After excavating the chunks, they reassembled the fossil to reveal its mysterious form. Oblong in shape, the fossil was gigantic, coming in around seven feet long and consisting of multiple lobes organized in an elliptical shape.

Further research dated the fossil to 450 million years ago, a time when life on Earth thrived in the water. Fine's dig site was underwater during that time, so the team assumed they had found some sort of strange sea monster. The fossil structure was unlike anything paleontologists had seen before. It consists of layers and oblong surfaces, much like a flattened cactus. Fine believes that creature stood up to 9 feet tall (which explains why he and his team named their find Godzillus), and had arms or branches radiating from the side.

Oddly, nobody knows if Godzillus was a plant or an animal. Fine's team theorized that it was a soft-bodied animal, which means 450 million years ago, there were 9-foot-long, slug-like giants wandering our ocean. Others believe it is merely a mat of algae, which sounds far more plausible, but also way less fun.

Homo floresiensis

Discovering new ancestors of modern humans is always fascinating, but sometimes completely baffling. When an Australian-Indonesian team discovered the fossils of a small hominid in 2003, they realized they would open new mysteries and questions about the human family. Indeed, their discovery, named Homo floresiensis, has forced researchers to rethink the human family history and the place of modern humans in it.

The hominid was diminutive, with samples averaging only a little over 3 feet tall, with big feet. Researchers began calling them Hobbits, which caused the Tolkien estate to threaten legal proceedings. Still, the nickname persisted, because what else are you going to call them?

So far, Homo floresiensis has only been found on one island in Indonesia, and records indicate they lived a mere 50,000 years ago. Since the Hobbits are so close in timeline to our own species, researchers are utterly baffled by them. Some contend that it's a totally separate species from humans, meaning Homo sapiens were not the only hominid species inhabiting the planet back in ancient times. This completely flies in the face of the old consensus Homo sapiens they were the only hominid species remaining when they took over the world. Others believe that the Hobbits were actually Homo sapiens who settled on Indonesia and, over centuries of inbreeding, developed dwarfism. Oddly, it seems like the second option has captured more steam among researchers, though if anybody digs up a shiny gold ring and dubs it their precious, all bets are off.

Chandra Wickramasinghe's meteorite fossils

Fossils don't just come from underground — now they can come from outer space! On December 29, 2012, a meteorite allegedly fell in Sri Lanka. We say "allegedly" because the International Meteorite Society did not record the impact, yet fringe scientists began studying the meteorite sample anyway, which was in good shape once recovered. While studying the dusty space rock, Chandra Wickramasinghe made a startling discovery: the meteorite had signs of fossilized life.

Wickramasinghe and his team published a paper outlining their discovery of diatom in the sample. These are microscopic phytoplankton that scientists use to monitor environmental conditions from the past. Diatoms preserve extraordinarily well in even the most extreme conditions. Wickramasinghe supposedly found multiple samples in the meteorite, which were in turn studied by diatom expert Patrick Kociolek, who verified that the microscopic creatures were diatoms, but noted that they shared similar evolutionary traits to diatoms on Earth. That means either the rock wasn't a meteorite, or life out in space took a similar evolutionary route to life on Earth.

Other scientists threw out the claim, believing that lightning actually formed the rock. Another hypothesis came forward that the rock was from both space and Earth, having been blasted into orbit during a bombardment event in the remote past. Among mainstream astrobiologists, Wickramasinghe's results are not taken seriously, but nobody has proven a better idea, so for now, consider him we shall.

Conrad's skull

Around 360 million years ago, Earth entered the Carboniferous Era, when carbon and swamps covered large parts of the land. Generally, life was becoming more modern during that era, with large plant populations and fish with the same characteristics as their modern brethren. However, no hominid samples have been traced back to that era, except for one mysterious skull found by Ed Conrad.

Conrad discovered the skull in 1981 in Pennsylvania. The skull was in an area of prehistoric coal, indicative of the Carboniferous Era. Conrad, and others, believe the skull had the same normal features of a human skull, but with one major complication: there was no evidence that hominids existed in the Carboniferous Era, hundreds of millions of years before the first known hominids appeared, roughly 4.5 million years back.

After doing more research on the skull, Conrad was sure that it was human and came from the Carboniferous Era, and dated it as roughly 280 million years old, but mainstream science did not support his claim, citing the whole "no humanoids back then" factoid most people just accept by now. In 2011, however, a study from Taiwan concluded that Conrad's fossil was, in fact, a human skull. Oddly enough, the story was picked up by creationists to show that Darwin was wrong when dating human life, though they seem unwilling to admit that this also means that a Biblical interpretation of the origins of life (that the world and everything in it is only 6000 years old) is also false.

The Nampa Stone Doll

Most people don't think of Idaho as a hotspot for archaeological mysteries, but it's actually the home of a mysterious figure that remains unexplained. The figure was dug up in 1889 when workers were digging a well in Nampa, right outside Boise. Resembling a human doll but made of stone and clay, the figure was buried 320 feet below the surface of the Earth. Finding a stone doll is weird enough — finding it that deep is a spine-tingling mystery.

The rock around the doll dated to 2 million years ago, far before any hominid made it to Idaho. This was also millions of years before Homo sapiens or comparable species walked the Earth, period. Paleontologists believe only Homo sapiens have the ability for this sort of workmanship, but they only appeared 200,000 years ago. Here is a stone doll that was at least a million and a half years older, with ornate designs that were clearly carved by hand. The right arm is even cemented to the doll, showing clear signs of artistic workmanship. This was certainly created by ancient humans that should not have existed at the time.

So, how did it get in the rock? Of course, skeptics have proposed a variety of mechanisms, including that it's fake. If it is evidence of ancient humans in Idaho, it would completely rewrite the evolutionary timeline of humanity, showing that Homo sapiens — or a currently-unknown, comparable species — existed way before we expected it. (It could also just be a fake.)

UC Riverside's mysterious circles

In 1986, scientists at the University of California-Riverside found a mysterious rock in Wisconsin, dated to back when the state was covered in water. The rock had mysterious circles on it, raised above the surface and perfectly circular. Scientists studied the weird rock for awhile and then, stumped, filed it away as an unsolved mystery.

Jump forward to 2015, and the fossil was still a mystery. Nobody could explain what could make perfect circles in the sea bed 450 million years ago. At a complete loss of ideas, UC Riverside scientists did what scientists rarely do: they opened it up to the internet and asked Reddit users to propose theories. Ideas ranged from sarcastic (typical for Reddit) to shockingly well-thought out. Some theorized that these were the work of prehistoric snails. Others though that jellyfish or sea sponges could have caused the shape. Overall, while the social media involvement was a success in brainstorming possible angles, none of the theories perfectly fit. All we know is what we already knew: 450 million years ago, something was making perfect circles on the seafloor in Wisconsin.

The Nevada giants

The Paiute Indians in Nevada tell stories of the Si-Te-Cah, a race of red-haired giants that had lived in Nevada for thousands of years before the Paiute settled the land. Other Indian tribes throughout the United States tell a similar story. According to the Paiute, the tribes unified to defeat the giants and finally kicked them out of their homeland after a protracted war.

Settlers to the West did not originally believe the Indians, dismissing the legends as pointless stories. That changed in 1911 when miners discovered Lovelock Cave while trying to harvest bat guano for fertilizer. The cave was huge, and the miners could see that it was previously inhabited. When they began digging, they discovered hundreds of ancient artifacts, along with huge bones that looked human, but that had to come from people nearly ten feet tall. The site garnered intense interest, and soon amateur archaeologists and paleontologists swarmed the area, discovering more huge bones that seemingly came from giants. Digging also revealed fossilized handprints that were much bigger than any human handprint.

The most interesting find, however, was the skulls. Each skull found had an oddly shaped jaw bone, and elongated features. Besides being bigger than a human skull, the features all point to a strange new species that existed in the Lovelock caves. The skulls are now held at a nearby museum, providing evidence that the Native American legend might be real. If so, that means at some point in the distant American past, there was an epic battle between Native Americans and giants.

End-Permian mass extinction fossils

Everyone knows that the dinosaurs died out from a giant asteroid collision, but few people know that the dinosaur extinction was not the only — or even the worst — mass extinction that our planet faced. There have been five, with the largest being the end-Permian event, which happened 252 million years ago. It is also the most mysterious. Fossil records show that 95 percent of all marine species and 75 percent of all terrestrial species went extinct during the event. The biodiversity loss was catastrophic, and it took millions of years to get back to pre-extinction levels.

But here's the weirdest part: Nobody knows why it happened. You'd think that such a traumatic event in the Earth's history would leave pretty definitive clues about what caused it, but that's not the case. For years, scientists have struggled to figure out why so many species died, seemingly out of nowhere. One leading theory is that intense global warming caused the extinction, leading to wide-scale ocean acidification that was absolutely deadly to marine life.

But other theories are much more exciting. Geologist Gregory Retallack has discovered microscopic fractures in quartz crystals that date from the time of the extinction, implying that some sort of massive force shook the Earth. According to Retallack, it could have been an asteroid collision, just like with the dinosaurs. An even more exotic theory held by many scientists is that coal in Canada and basalt in Siberia might have blown up out of nowhere, causing a huge ash cloud and making almost all life on Earth go extinct.

The Atacama 'alien'

There's no denying this one's weird enough to make the most determined alien denier stop and rethink their position. According to the Smithsonian, a 6-inch-long skeleton was discovered in a Chilean ghost town in 2003. (Found in the Atacama Desert, the mummy has been nicknamed Ata.) Despite looking vaguely human, there are other oddities. (Besides, of course, the size.) There's the pointed skull, the giant eye sockets, and two missing ribs. Surely, that's all the proof you need that aliens are real, right? The tiny mummy provided some serious fuel for believers, but in 2018, scientists revealed part of the puzzle

The mummy's DNA confirmed she is very human, and she's even a local. But researchers from Stanford University kept digging, and got more questions than answers. Initially thought to be ancient, scientists eventually determined the remains were only around 40 years old. They also found that while you'd think her size could be explained by simply stating she was born prematurely, her bone structure was as developed as that of a 6-year-old.

She also had a shocking number of genetic mutations, a list that included variants linked to things like dwarfism and scoliosis. But the list also contained mutations that scientists were confused by — in all, 54 rare mutations that possibly describe diseases and conditions modern science has never seen and can't explain. So Ata isn't an alien, but it might be less weird if she were.