The shifting sands of the Sahara have swallowed animals, people, and entire cities over eons. It is the largest hot desert in the world, and those who become lost in its endless sandy plains are likely to never be seen again. In the ancient world, whole armies were known to march off across it, never to be seen again.

Only now, with modern technology, are we beginning to penetrate all of the Sahara’s mysteries—and there are quite a few of them. Here are ten amazing discoveries that the Sahara Desert has been hiding from us.

10 Lost Fortresses

Satellites have allowed explorers to peer beneath the canopies of the densest jungles and pierce the heart of the most inhospitable deserts—all without the bother of even leaving one’s chair. In 2010, satellites detected the remains of more than 100 fortresses belonging to the Garamantes people of Libya.^[1] The area had been well-mapped by the oil industry searching for places to drill, so archaeologists were able to scan their satellite pictures for the telltale signs of walls. Later, researchers on the ground were able to confirm that the structures were indeed built by the Garamantes, though their expeditions were cut short by the revolution in Libya which toppled Colonel Gadhafi.

At the time the Garamantes flourished (approximately the second century BC to the seventh century AD), the area they lived in was already incredibly arid. To farm their land, they constructed underground channels that provided water from ancient reservoirs. When this water source failed, the fields withered, and the Sahara covered over the remains of the fortresses and villages.

9 Meteorites And Craters

The Earth has always been bombarded by rocks and meteorites from outer space. Most burn up harmlessly in the atmosphere, leaving nothing more than a streak of light across the sky. Others reach the ground and have devastating impacts. Because most happened in the distant past, the craters left behind by such impacts are often overlooked because erosion or plant growth covers them up. In deserts, however, the scars can still be seen. The 45-meter-wide (148 ft) Kamil Crater in Southwestern Egypt still obviously indicates where an iron meteorite struck around 5,000 years ago.^[2]

It is not just the craters left by meteorites that can be found, however. Around the Kamil Crater, fragments of the meteorite itself have been discovered from where the impact shattered it and scattered it across the sand. This is not an isolated discovery. Almost a fifth of all meteorites that have been recovered have come from the Sahara. This is because on the sands, meteorites stand out, often just waiting to be picked up. Only the snows of Antarctica provide a better place to go meteorite-hunting.

8 Libyan Desert Glass

Even when the remains of meteorites and their craters have vanished, other traces of cosmic collisions can remain. Around 29 million years ago, a meteorite struck the Earth with enough energy to melt a vast region of the Libyan desert into sheets of delicate green glass.^[3] The crater left by this explosion has yet to be found, but plenty of the desert glass still exists—and in some unexpected places.

When Howard Carter opened the tomb of Tutankhamun, he discovered among the treasures a jeweled breastplate (also referred to as a pectoral) belonging to the dead king. At its center was a sacred scarab beetle carved from green glass. The Egyptians probably had no idea of the origin of the glass they used, but intriguingly, there was another artifact made from otherworldly material. One of the daggers in the tomb was created from iron that came from a meteorite.

7 Nabta Stones

Wherever water can be found in a desert, you will find life clinging on. When people lived near Nabta Playa in Southern Egypt 9,000 to 6,000 years ago, the area was subject to annual flooding, which created a lake. Neolithic tribes came there to feed and water their animals.^[4] These people not only survived there, but they developed a culture of sacrifice. Cows, sheep, and goats have all been found ritually buried there.

Around 6,000 years ago, the people at Nabta set up large stone blocks in a circle, with more slabs of rock radiating outward. (A mock-up is pictured above.) It has been claimed that this stone circle, which predates Stonehenge by 1,000 years, is the earliest known astronomically aligned structure. There is still debate as to what exactly the circle points to, but one researcher claims that it lines up with the position of Orion’s Belt, as it would have appeared in the sky 6,000 years ago.

6 Lost River

The Sahara Desert has not always existed. As the climate changed over millions of years, the borders of the sands have shifted. Just as scientists can search for ancient evidence of water on Mars, so have they turned their attention to the history of the Sahara. Research has revealed that what would once have been the world’s 12th-largest drainage basin flowed from within the Sahara.

The remains of the river in Mauritania were noticed when an undersea canyon off the coast was discovered that had been carved by the river. River sediments also turned up in unexpected places. The final confirmation of the presence of a lost river was made by satellite.^[5] The lost river is now called the Tamanrasett River, and research is continuing to discover more about a body of water that may have dried up just 5,000 years ago.

5 Whales

It’s not just rivers that have disappeared under the Sahara. Over geological time, what was once an ocean has become one of the driest places on Earth. In Wadi Al-Hitan in Egypt, evidence of the lost Tethys Ocean can be found. Known as Whale Valley, it is one of the best, if unlikely, sites for discovering whale fossils.^[6] The fossils here give insights into how whales evolved from land-dwelling creatures to ones that spent their entire lives at sea.

When the ancestors of modern whales died in the sea 37 million years ago, their bodies were covered with sediment. As the crust of the Earth rose, their former home was turned to land. Today, the 15-meter-long (50 ft) skeletons are being studied by paleontologists, as are the creatures they shared the sea with. Beside the whale bones, the teeth of large and vicious sharks have been found.

4 Machimosaurus Rex

The seas have always been home to monsters. Some 120 million years ago, a 9-meter-long (30 ft) crocodile, Machimosaurus rex, called what is now the Sahara Desert its home. M. rex is the largest ocean-dwelling crocodile known to have existed. The area where M. rex once lived was probably a vast lagoon which stretched to the Tethys Ocean. There, it used its huge head, incredible bite strength, and short, brutal teeth to crack the shells of ocean turtles and snatch fish.^[7] It may also have scavenged on the carcasses of the large creatures which also shared its home.

If it seems ironic that so much marine life is being uncovered in the Sahara, it’s really because the desert is so inhospitable to life that paleontologists are making so many discoveries there. Without plants and soil getting between them and the rocks beneath, scientists are often able to simply stroll through eroding areas to pick up amazing findings.

3 Spinosaurus

Continuing the theme of nautical discoveries made in a desert, Spinosaurus is the largest carnivorous dinosaur ever discovered. Living 95 million years ago, Spinosaurus (aka Spinosaurus aegyptiacus) stood around 7 meters (23 ft) tall and measured 16 meters (52 ft) long, exceeding the better-known T. rex. Spinosaurus looked, and lived, nothing like its better-known rival. Spinosaurus had a huge sail of bones sticking up from its back and a number of other adaptations that have baffled scientists. Now, it is thought that Spinosaurus is the only known truly semiaquatic dinosaur.

Since the bones of the originally discovered Spinosaurus were destroyed in World War II, it was not until another set of fossils were discovered in Morocco that researchers were really able to study Spinosaurus. Among the evidence pointing to Spinosaurus living partly in the water are its long, flat feet for paddling, as well as the nostrils placed high on its snout to allow it to breathe even when mostly submerged.^[8] Seeing the huge sail on its back approaching must have chilled inhabitants of ancient waterways in much the same way a shark’s fin does for us today.

2 World War II P-40 Kittyhawk P-40

On June 28, 1942, Flight Sergeant Dennis Copping was flying a damaged P-40 Kittyhawk to a British base in the desert for repairs. Somewhere on the journey, both the aircraft and its young pilot disappeared.^[9] Only in 2012 were the remains of the plane discovered when an oil worker stumbled across them. The aircraft was mostly intact, having never been disturbed, and there was still evidence of a parachute having been used to create a shelter.

The plane was later taken to El Alamein Museum and restored—not to everyone’s satisfaction. Some felt the aircraft should have remained where it was as a memorial to its young pilot. Others thought that the restoration job the museum did made it look like poorly painted model. While the plane was recovered, no signs of Dennis Copping were found. His exact fate is another mystery that the Sahara is holding.

1 Gobero Skeletons

Paul Sereno has already featured on this list, as he was part of the team which found more fossils of Spinosaurus. It was during one of his dinosaur-hunting trips that he accidentally found the largest human graveyard in the Sahara. The site at Gobero in Niger was inhabited as early as around 10,000 years ago and shows that it was once a more green and lush environment. The remains of fish, crocodiles, and other animals are mixed in among the humans.^[10] Many of the discoveries were simply poking out of the sand. Two years of excavation revealed around 200 human burials and pointed to two separate periods of habitation separated by more than 1,000 years.

The Kiffians and the Tenerians both left traces of their lives behind. Bone jewelry and arrowheads were discovered alongside harpoons that would have been used to hunt in the nearby waters. Many of the burials were strikingly unusual. One man was buried with his head in a pot, while another rested on the remains of a turtle shell. Perhaps we will never know exactly how these people lived and died. The Sahara is not giving up all its secrets.

You can follow Ben on Twitter @BenTheEpicure.

Deserts are typically portrayed as empty wastelands. Although their surface does not have a lot to offer, there is plenty to discover underneath. Archeologists have been digging up fossils in deserts for decades—especially the Sahara Desert, the biggest hot desert in the world.

Scattered across the globe, fossils are traces of organisms from a past geologic age that have been embedded and preserved in the Earth’s crust. But despite fossils’ wide range, the Sahara Desert contains many of the oldest, biggest, and most unusual fossils ever found. These ancient relics grant insight into the history of our planet and many creatures, including humans.

10 Giant Catfish

An ancient relative of the well-known catfish was plucked from the sands of Egypt in 2017. The new species was named Qarmoutus hitanensis and is believed to have lived roughly 37 million years ago.

At about 2 meters (6.5 ft) long, this specimen would be on the upper end of the catfish size scale. Qarmoutus hitanensis represents an entirely new genus and species, making it an intriguing early branch on the catfish family tree.

According to John Lundberg from Drexel University’s Academy of Natural Sciences, the ancient fossil is more like the modern-day catfish than one would expect. “Even though the fossil is relatively old in the way we ordinarily think of ages in millions of years, it is still essentially anatomically modern and directly comparable to living catfishes,” said Lundberg. “It’s one of the best preserved and oldest of its family.”^[1]

9 Massive Crocodile

In 2014, paleontologists discovered the remains of one of the biggest crocodiles ever found. Named Machimosaurus rex, this prehistoric beast was twice the size of any crocodiles seen today. It would have weighed at least 2,993 kilograms (6,600 lb) and been around 9.8 meters (32 ft) long. The fossil was buried in Tunisia on the edge of the Sahara Desert.

The Machimosaurus rex was likely a top predator in what was then an ocean that separated Africa from Europe about 130 million years ago. “The skull itself is as big as I am,” explained Federico Fanti from the University of Bologna who was part of the team that made the discovery. “Just the skull is more than five feet long. It’s a massive crocodile. He was so big and so powerful that it was absolutely at the top of the food chain.”^[2]

Besides its size, this find is also significant because these crocodiles were believed to have died out in a mass extinction event between the Jurassic and Cretaceous periods about 150 million years ago. The discovery suggests that the extinction event was not as widespread as some paleontologists thought.

“Everyone thought this group of crocodiles went extinct in the Jurassic, but we found it well into the Cretaceous,” said Fanti. “We simply extended the temporal range of the animals. Twenty million years is a lot of time.”

8 Spinosaurus Fossil

Spinosaurus is well-known in the scientific community as one of the largest carnivorous dinosaurs to have ever lived. But one giant fossil unearthed in 2014 in the Sahara Desert has given scientists an unprecedented look at the creature. The 95-million-year-old remains confirmed a theory that this is the first swimming dinosaur that we know of.

Scientists say that the beast had flat, paddle-like feet and nostrils on top of its crocodilian head that would allow it to submerge with ease. Other ancient creatures that lived in the water, such as the plesiosaur and mosasaur, were marine reptiles rather than dinosaurs, making Spinosaurus the only known semiaquatic dinosaur.

Nizar Ibrahim, a paleontologist from the University of Chicago, said:

It is a really bizarre dinosaur—there’s no real blueprint for it. It has a long neck, a long trunk, a long tail, [a 2.13-meter (7 ft) sail] on its back, and a snout like a crocodile. And when we look at the body proportions, the animal was clearly not as agile on land as other dinosaurs were, so I think it spent a substantial amount of time in the water.

Although the first Spinosaurus remains were discovered around 100 years ago in Egypt, they were destroyed during World War II when an Allied bomb hit a museum in Munich, Germany. A few drawings of the fossil survived, but only fragments of Spinosaurus bones were found ever since. The new fossil extracted in eastern Morocco has provided scientists with a more detailed look at the dinosaur.

“For the very first time, we can piece together the information we have from the drawings of the old skeleton, the fragments of bones, and now this new fossil, and reconstruct this dinosaur,” said Ibrahim. “The hind limbs were shorter than in other predatory dinosaurs, the foot claws were quite wide, and the feet almost paddle-shaped.”

As time went on, the scientists continued to find more proof of the creature’s aquatic life. Ibrahim noted:

The snout is very similar to that of fish-eating crocodiles, with interlocking cone-shaped teeth. And even the bones look more like those of aquatic animals than of other dinosaurs. They are very dense and that is something you see in animals like penguins or sea cows, and that is important for buoyancy in the water.^[3]

7 Legged Whales

Wadi Al-Hitan (“Whale Valley”) is a paleontological site in the Al Fayyum Governorate of Egypt around 150 kilometers (93.2 mi) southwest of Cairo. It was designated a UNESCO World Heritage Site in 2005 after hundreds of amazing fossils were discovered in the area.

The valley got its name due to an incredibly high concentration of high-quality marine fossils. The most important discovery at the site is believed to be an extinct suborder of whales called Archaeoceti. These fossils represent a key piece in the story of evolution—the emergence of the whale as an ocean-going mammal from a previous life as a land-based creature.

The first whale skeletons were discovered in 1902. Initially, the site attracted relatively little interest because it was difficult to reach. That changed when four-wheel-drive vehicles became more readily available in the 1980s.

The largest skeleton found reached 21 meters (69 ft) in length, with well-developed five-fingered flippers on the forelimbs and the unexpected presence of hind legs, feet, and toes not known previously in any Archaeoceti.

Besides whales, hundreds of other marine creatures such as crocodiles, turtles, sharks, and rays have been uncovered. Some fossils are so well-preserved that their stomach contents are still intact. The incredible quality and quantity of the remains make it possible for scientists to reconstruct the surrounding environmental and ecological conditions of the time.^[4]

6 480-Million-Year-Old Mystery Creature

A mysterious creature that lived hundreds of millions of years ago was hotly debated by scientists for 150 years since its initial discovery in the 1850s. The mystery was finally unraveled in early 2019 when new stunningly detailed fossils discovered in Morocco allowed paleontologists to identify the bizarre creature.

These life-forms, known as stylophorans, looked like flat armored wall decorations with a long arm poking off their sides. Previously, scientists were not even sure if they fit in the animal family tree. However, the new study revealed that the creatures were echinoderms—ancient relatives of animals such as starfish, sea lilies, sea urchins, feather stars, and sea cucumbers.

Lead researcher Bertrand Lefebvre said that the findings were possible thanks to fossils with “unequivocal evidence for exceptionally preserved soft parts, both in the appendage and in the body of stylophorans.” Although the incredible fossils were unearthed along the edge of the Sahara Desert in 2014, researchers didn’t immediately realize that some of the 450 excavated stylophoran specimens included preserved soft tissues.

“This discovery is of particular importance because it brings to an end a 150-year-old debate about the position of these bizarre-looking fossils in the tree of life,” Lefebvre said.^[5]

5 World’s Oldest Biological Color

A team of scientists discovered the oldest color in the geological record beneath the Sahara Desert in 2018. The excavated fossils appeared to have a variety of colors.

Originally green, the fossils became bloodred to deep purple in their concentrated form. However, once diluted, the fossils revealed a bright pink pigment in an oil form. This bright pink pigment is believed to be 1.1 billion years old.

According to Nur Gueneli from The Australian National University, the ancient pigment was extracted from marine black shales of the Taoudeni Basin in Mauritania, West Africa. Gueneli said that the pigment resulted from molecular fossils of chlorophyll that were processed by ancient photosynthetic organisms that used to rule the oceans.

“Of course, you might say that everything has some color,” said senior lead researcher Jochen Brocks. He compared the discovery to finding an ancient T. rex bone. “It would also have a color, it would be gray or brown, but it would tell you nothing about what kind of skin color a T. rex had.”

Brocks continued, “If you would now find preserved, fossilized skin of a T. rex, so that skin still has the original color of a T. rex, say it’s blue or green, that would be amazing.”

Then he concluded, “That’s in principle what we’ve discovered . . . only 10 times older than the typical T. rex. And the molecules we’ve found were not from a large creature but microscopic organisms because animals didn’t exist at that time. That’s the amazing thing.”^[6]

4 New Pterosaur And Unknown Sauropod

The discovery of a new dinosaur species is a rare occurrence, but discovering two new species in one expedition is any paleontologist’s dream. One team of paleontologists made that dream a reality in 2008 when they unearthed a new pterosaur and a previously unknown sauropod dinosaur in the Sahara Desert.

The pterosaur was identified by a large fragment of the flying reptile’s beak, while the sauropod was represented by a long bone measuring more than 0.9 meters (3 ft) long. It indicated an herbivore, nearly 20 meters (65 ft) in length. Both these extinct giants would have lived almost 100 million years ago.

Pterosaur remains are particularly uncommon because their light and flimsy bones, optimized for flight, are rarely found in a well-preserved state. Nizar Ibrahim, then a graduate student at University College Dublin who led the expedition, stated: “Most pterosaur discoveries are just fragments of teeth and bone, so it was thrilling to find a large part of a beak, and this was enough to tell us we probably have a new species.”^[7]

3 Fish Fossils Lead To Ancient Mega-Lake Discovery

In 2010, scientists discovered evidence of a prehistoric mega-lake that had formed beneath the sands of the Sahara around 250,000 years ago when the Nile River flooded the eastern Sahara. At its highest level, the lake covered over 108,780 square kilometers (42,000 mi²) and reached a height of 247 meters (810 ft) above sea level.

Scientists estimate that the Nile once flooded the entire Kiseiba-Tushka depression of Egypt and created the massive lake. Deposits of fish fossils found about 402 kilometers (250 mi) west of the Nile played an important part in the discovery and were used as a sea-level marker of the lake’s highest shoreline.

Researchers also used radar data of Egypt taken by the Space Shuttle Radar Topography Mission. Geologists pieced together the profile of the mega-lake by using images of windblown sediments, sediments produced by running water, and bedrock beneath the desert sands.^[8]

A different set of archaeological sites near Bir Kiseiba, 150 kilometers (93 mi) west of the Nile, suggests a second level of the lake at 190 meters (623 ft) above sea level. The lower-level lake is believed to have covered 48,174 square kilometers (18,600 mi²). It adds to growing evidence of numerous Early and Middle Pleistocene lakes across North Africa, which could have supported human migration patterns.

2 Holy Grail Of Dinosaur Fossils

In 2013, a team of scientists from the Mansoura University Vertebrate Paleontology (MUVP) unearthed what has been described as the holy grail of dinosaur fossils—a near-complete, school-bus-sized dinosaur from the Cretaceous era. The well-preserved remains belong to a titanosaurian sauropod, a type of long-necked, herbivorous dinosaur that lived around 94 to 66 million years ago.

The dinosaur, dubbed Mansourasaurus shahinae gen, was discovered in the Quseir formations of the Dakhla Oasis in Egypt’s Western Desert. It was the sixth and youngest dinosaur to be discovered in Egypt. According to Hesham Sallam, lead author of the study, the fossils represent the most complete remains belonging to a dinosaur of this era in the entire African continent.

“The discovery and extraction of Mansourasaurus was such an amazing experience for the MUVP team,” said Sallam. “It was thrilling for my students to uncover bone after bone, as each new element we recovered helped to reveal who this giant dinosaur was.”^[9]

1 Oldest Fossils Of Homo sapiens

Miners in Morocco dug up a few skull pieces at a site called Jebel Irhoud in 1961. A few more bones were found in later digs along with flint blades and charcoal, indicating the use of a campfire. Researchers initially estimated the remains to be 40,000 years old until a paleoanthropologist named Jean-Jacques Hublin inspected one jawbone in the 1980s.

While the teeth were similar to those of living humans, the jawbone’s shape seemed strangely primitive. “It did not make sense,” Dr. Hublin recalled in an interview. In 2004, Dr. Hublin and his colleagues started working through layers of rocks on a desert hillside at Jebel Irhoud. Since then, they have found many fossils including skull bones from five individuals who had all died around the same time.

The scientists also discovered important flint blades in the same sedimentary layer as the skulls. People of Jebel Irhoud probably lit fires to cook food, heating discarded blades buried in the ground below. This made it possible to use the flints as historical clocks.

Through a method called thermoluminescence, Dr. Hublin and his colleagues calculated that the blades were burned roughly 300,000 years ago. As the skulls were discovered in the same rock layer, they must have been around the same age. Despite their old age, anatomical details showed that the teeth and jaws belonged to Homo sapiens, not another hominin group such as the Neanderthals.^[10]

However, the researcher’s claim is controversial. Anthropologists are still debating what exact physical features distinguish modern humans from our ancestors. The previous oldest-known bones widely recognized as Homo sapiens are around 200,000 years old. The new discovery pushes the date of the emergence of our species back another 100,000 years.