Category Archives: MEXICO

2,000-Year-Old Realistic Green Mask Found Nestled Inside an Ancient Pyramid

2,000-Year-Old Realistic Green Mask Found Nestled Inside an Ancient Pyramid

Alejandro Sarabia, Saburo Sugiyama, Enrique Perez Cortes & Nawa Sugiyama have reported this discovery,  announced this finding registered during explorations conducted in the 65-meters high pyramidal structure from 2008 to 2011.

The 116-meter-long tunnel drilled in 1930 by the archaeologist Eduardo Noguera was used to excavate 59 stratigraphic wells and 3 short tunnels by the Pyramid of the Sun project led by Alejandro Sarabia in order to enter the mother rock floor, to check the existence of burials and offerings.

“We know if the Teotihuacan’s had put anything inside the monument they would have happened at the tepetate level, so we did a quick test right at the end of the tunnel and a short conduct to reach the centre of the pyramid since Noguera tunnel was carved approximately 6 metres to the west of the centre of the monument”, said Perez Cortes. During the course of the excavation, 3 architectural structures built before the Pyramid of the Sun and 7 human burials, some of them referring to infants, were found, which were buried before the completion of the building, as well as 2 offerings, one of the great richness.

The sumptuous offering was discovered at the meter 85 of the tunnel, inside the constructive filling, “so we know it was deposited as part of a consecration ceremony of the structure, probably at the beginning of its construction more than 1900 years ago” mentioned Perez Cortes, the researcher at Zacatecas INAH Center.

The rich deposit, where a greenstone mask outstands, was integrated by several levels of objects; since the area of archaeological material extended to the south of the limits of the probing well, they decided to expand the exploration.

Objects that integrate the offering “were elaborated with different materials and techniques; a considerable amount of obsidian pieces outstand, such as projectile heads, small knives, an anthropomorphic eccentric artefact and 3 anthropomorphic figures adorned with shell and pyrite eyes, also accompanied by projectile heads”.

Among the 3 greenstone sculptures found, outstands an extraordinary anthropomorphic mask carved out in one piece, with eyes inlayed in pyrite and shell, declared Perez Cortes; the serpentine mask, according to studies conducted by Dr Jose Luis Ruvalcaba, from the National University Physics Institute (IF UNAM), is the only greenstone mask discovered until now in the ritual context of Teotihuacan.

The 11 centimetres high, 11.5 wide and 7.8 cm deep mask is different to other Teotihuacan masks because it presents smaller dimensions and has volume; it is possible that it was a portrait. A seashell was found next to the sculpture.

2,000-Year-Old Realistic Green Mask Found Nestled Inside an Ancient Pyramid

The offering also contained 11 Tlaloc vessels, most of them fragmented, placed in the centre of it. Other objects deposited include 3 pyrite discs, being the one with 45 centimetres diameter mounted on a slate slab the greatest recovered until now in Teotihuacan.

An important amount of animal skeletons was found. The skull of a feline was placed to the northeast; a canine to the south and an eagle covered with volcanic rock, to the southeast. The bird was fed before the sacrifice with 2 rabbits, as analyses reveal.  This kind of fauna is similar to the one found at offerings of the Pyramid of Moon. Researchers from the Pyramid of Sun Project at Teotihuacan Archaeological Zone (ZAT) remarked that the offering remained underwater since the humidity of the monumental structure concentrates on the base and central area.

Dr Saburo Sugiyama, professor at Aichi University, Japan, and Alejandro Sarabia, director of the archaeological zone located in Estado de Mexico, indicated that for a long time before the discovery, the function of the pyramid was linked to the underworld because of the tunnel excavated by Teotihuacan people.

“Nevertheless, objects found would be indicating that the Pyramid of the Sun –which covers an approximate area of 5.6 hectares- was possibly offered to a rain deity, an early version of Tlaloc, during the first 50 years of the Common Era”.

“Until now, we can only offer a general interpretation of the findings, although it is evident that some of them present the same distribution pattern already observed at the Pyramid of the Moon burials”, concluded the specialists.

History of “Pyramid of Sun”:

The Pyramid of the Sun is the largest building in Teotihuacan and one of the largest in Mesoamerica. Found along the Avenue of the Dead, in between the Pyramid of the Moon and the Ciudadela, and in the shadow of the massive mountain Cerro Gordo, the pyramid is part of a large complex in the heart of the city.

The name Pyramid of the Sun comes from the Aztecs, who visited the city of Teotihuacán centuries after it was abandoned; the name given to the pyramid by the Teotihuacanos is unknown. It was constructed in two phases. The first construction stage, around 100 A.D., brought the pyramid to nearly the size it is today.

The second round of construction resulted in its completed size of 738 feet (225 meters) across and 246 feet (75 meters) high, making it the third-largest pyramid in the world, but being much shorter than the Great Pyramid of Giza (146 meters). The second phase also saw the construction of an altar atop the pyramid, which has not survived into modern times. The Adosada platform was added to the pyramid in the early third century, at around the same time that the Ciudadela and Temple of the Feathered Serpent, Teotihuacan Pyramid of the Feathered Serpent were constructed.

Over the structure, the ancient Teotihuacanos finished their pyramid with lime plaster imported from surrounding areas, on which they painted brilliantly coloured murals. While the pyramid has endured for centuries, the paint and plaster have not and are no longer visible. Few images are thought to have been included in the mural decorations on the sides of the pyramid. Jaguar heads and paws, stars, and snake rattles are among the few images associated with the pyramids.


It is thought that the pyramid venerated a deity within Teotihuacan society but the destruction of the temple on top of the pyramid, by both deliberate and natural forces prior to the archaeological study of the site, has so far prevented identification of the pyramid with any particular deity. However, little evidence exists to support this theory.

137 children’s handprints discovered in Yucatán cave

137 children’s handprints discovered in Yucatán cave

More than 100 black and red handprints were discovered on the walls of a cave in Mexico, possibly created during an ancient Mayan ritual. Archeologists said most of the 137 prints were made by children some 1,200 years ago and that it was part of a tradition when children entered puberty.

Sergio Grosjean pointing out 1,200-year-old children’s handprints in a cave in Mexico.

The cave, located near the northern tip of the Yucatan Peninsula, is surrounded by large pyramid-like ruins and sits some 33 feet beneath a Ceiba tree that is considered sacred in Mayan beliefs.

Archeologist Sergio Grosjean, who currently is working at the site, said: ‘They imprinted their hands on the walls in black… which symbolized death, but that didn’t mean they were going to be killed, but rather death from a ritual perspective.’

‘Afterwards, these children imprinted their hands in red, which was a reference to war or life.’

The Mayan rite of passage was for both boys and girls.

More than 100 black and red handprints discovered on the walls of a cave in Mexico were created during an ancient Mayan ritual. Archeologists say most of the 137 prints were made by children some 1,200 years ago and believe it was part of a coming-of-age ritual when children entered puberty.

Girls of the tribe would receive a shell to wear around their waists, indicating they were of age to have children.

Boys, however, went on their first hunt and performed a bloodletting ritual to confirm that they could be viewed as men. After completing the ritual, they received a white bead to wear in their hair and moved to an area in the community known as a ‘home of unmarried men’ until marriage.

Handprints in a cave had not been discovered by experts before. Along with the handprints, archeologists found a carved face and six painted reliefs, which date from between 800 through 1000 AD. In 1000 AD, a severe drought struck the region and contributed to the Mayans’ sudden abandonment of major cities.

While the first Mayan settlements date back nearly 4,000 years, large groups existed when Spanish conquerors arrived in the early 1500s.

In June 2020, archeologists discovered a 3,000-year-old Mayan temple, making it the ancient civilization’s oldest and largest known monument. The site in Tabasco, Mexico, had been discovered in 2017 by international team archaeologists led by the University of Arizona.

The site, called Aquada Fénix, is 4,600 feet long and up to 50 feet high, making it larger than the Mayan pyramids and palaces of later periods.

It was built between 800 BC and 1000 BC, according to the team behind the discovery.

One of the most remarkable revelations from the find was the complete lack of stone sculptures related to rulers and elites, such as colossal heads and thrones, which are commonly seen in other Mayan temples.

This suggests that early Mayans were more egalitarian than later generations.

Archaeologists discover a secret Aztec tunnel built 600 years ago by emperor Moctezuma

Archaeologists discover a secret Aztec tunnel built 600 years ago by emperor Moctezuma

Archaeologists from the National Institute of Anthropology and History (INAH) discovered 11 pre-Hispanic images in a tunnel in Ecatepec, México’s state capital, that is part of a colonial dike system.

Petroglyphs and stucco relief panels were among the photos found on the sides of the 8.4-meter-long tunnel, according to INAH.

The tunnel is part of the Albarradón de Ecatepec, a four-kilometer-long 17th-century dike system.

Archaeologists discover a secret Aztec tunnel built 600 years ago by emperor Moctezuma
Archaeologists have unearthed a secret Aztec tunnel chamber that has been hiding under the bustling streets of Mexico City for more than 600 years

A war shield, the head of a bird of prey, and a “paper ornament” are among the images carved into the walls of the tunnels while a teocalli, or temple, is etched into the central stone of the arch entrance.

The temple is dedicated to the rain god Tláloc, the INAH archaeologists concluded.

Some of the images are still being studied to determine their exact nature and meaning.

Raúl García, coordinator of a project to preserve the archaeological treasures of the dike system, said that one hypothesis is that the images were made by indigenous people who lived in the pre-Hispanic towns of Ecatepec and Chiconautla. Residents of both towns worked on the construction of the dike, he said.

Adorned with carvings and paintings, the passageway that dates back to the 15th century is believed to have been built by Emperor Montezuma I and linked to the god of water and fertility – Tlaloc

The archaeologist explained that the tunnel where the images were discovered is in a section of the dike known as the Patio de Diligencias.

The glyphs and stucco panels, all of which have been damaged by hundreds of years of rain, will be covered for protection, García said.

The Albarradón de Ecatepec was declared a historical monument in 2001 and will soon be incorporated into a public park.

México state INAH director Antonio Huitrón said the opening of the park will allow people to enjoy the “cultural heritage to which they are heirs.”

The tunnel where the images were discovered will also be open to the public although the originals won’t be on display.

The site in which the wall was found is part of a more than decade long conservation project around la Calzada de San Cristobal

Aztecs were famous for their agriculture, introducing irrigation, draining swamps, creating artificial islands in the lakes and building intricate structures like

Huitrón said the stones featuring the petroglyphs and stucco panels will be removed and transferred to the Casa Morelos Community Center in Ecatepec. Stones with replicas of the images will be installed in their place, he explained.

Ecatepec, Mexico’s second most populous municipality, is located just north of Mexico City and is part of the Valley of Mexico metropolitan area.

In 1980, while cleaning out her garage, a woman found the hidden mummies

In 1980, while cleaning out her garage, a woman found the hidden mummies

In 1966, two California teenagers became fascinated with mummies and archaeology. They wanted to make a find for themselves and had heard that the prehistoric tribes of northern Mexico had a tradition of burying their dead in caves.

Near Sunny San Diego, the small area known as Lemon Grove is famous for its Giant Lemon, a sight to behold for all roadside novelty-seekers. Also, mummies. 

What do you do when your earnest search for a mummy actually yields one? What if it yields two? If you are the two teenage boys who managed to find this treasure trove of mummification, you panic and hide them in a garage. 

In 1966, two California boys went to Chihuahua, Mexico in search of mummies. Quite the mummy fanatics, they knew Indian tribes had once brought their dead to the cool, dry caves near Chihuahua, and considered the area prime hunting grounds for a mummy of their very own.

The mummies were found in a cave in Chihuahua, Mexico

For over a month they peeked into every nook and cranny of the caves, until their tenacity finally paid off—the boys not only found a coveted mummy, they found two.

The boys gazed at their prizes, the mummified remains of a teenage girl, as well as the tinier corpse of a one-year-old. Despite their determination to find them, they were now faced with the reality of having them.

They couldn’t exactly carry the bodies out of the country in backpacks, and the gravity of their mothers finding out began to become a very worrisome, previously overlooked issue. So the boys did what any secret-keeping teen would—they smuggled the bodies over the border, and convinced a friend to hide them in her garage. 

With no real endgame in sight the boys left their macabre finds in this safe location—safe that is until their friend’s mother decided that it was tie to do some spring cleaning. 14 years after being stashed away behind the garden tools and moving boxes, the girls were found.

The woman who found them was understandably shaken and naturally assumed that some sort of murder had taken place. Stolen mummies stashed there by neighbor kids isn’t exactly the first place the mind goes.

The police recognized immediately that the bodies were not likely to be murder victims, but could not figure out how the two ancient cadavers found their way into this suburban family garage—the teen is thought to have died between  A.D. 1040 and 1260. While they investigated, the mummies were delivered to the San Diego Museum of Man for safekeeping. 

Fondly nicknamed “The Lemon Grove Girl”, the teenage mummy and her infant companion were stashed away until rightful ownership could be sorted.

Eventually the police caught up with the boys, who were now grown men of course, and asked for an explanation. The men told their story, and in an ever so generous act of contrition offered to donate their mummies to the Museum of Man. 

The officials, eyes rolling, informed the men that due to their juvenile status when the crime was committed and the time that had passed, they were lucky that no charges would be pressed, and thanked them for the charitable offer, but the mummies were not theirs to give.

The museum however was very keen on becoming the keeper of the girls, and after being granted permission by the Mexican government to retain them, including the Lemon Grove Girl in their gorgeous Ancient Egypt and Mummies exhibit. 

Fossil of 67 million-year-old Raptor Dinosaur Found in New Mexico

Fossil of 67 million-year-old Raptor Dinosaur Found in New Mexico

Experts have discovered dinosaur fossils of what they believe is one of the last remaining species of raptors, a 67-million-year-old known as Dineobellator notohesperus.

The new species of dromaeosaurid — a species of “generally small to medium-sized feathered carnivores” —was discovered in the San Juan Basin, New Mexico, according to a study published in Scientific Reports. D. notohesperus lived during the Cretaceous period, which ended 66 million years ago.

The study’s authors noted a “number of unique features, including vertebrae near the base of the tail that curved inwards, which could have increased Dineobellator’s agility and improved its predation success,” according to a press release.

Illustration of three Dineobellator near a water source, with the ceratopsid Ojoceratops and sauropod alamosaurus in the background.

There is also a gouge mark on the fossil’s sickle-shaped claw, that the researchers believe could have been “inflicted during an altercation with another Dineobellator or other theropod such as Tyrannosaurus rex.”

Phylogenetic analysis of the dinosaur suggests it could be part of the Velociraptorinae subfamily, which also includes velociraptors, famous for their appearance in the “Jurassic Park” movies.

Though small in stature, at approximately 7 feet in length, this carnivorous dinosaur had huge claws and a tail that was flexible at its base, allowing it to increase agility and change direction, according to the study’s lead author, Steve Jasinski.

“Think of what happens with a cat’s tail as it is running,” said Jasinski in a release from the University of Pennsylvania. “While the tail itself remains straight, it is also whipping around constantly as the animal is changing direction.

A stiff tail that is highly mobile at its base allows for increased agility and changes in direction and potentially aided Dineobellator in pursuing prey, especially in more open habitats.”

Dinosaurs were wiped out 65 million years ago by an asteroid that hit Earth in what is now the Yucatan Peninsula in Mexico. It not only wiped out the dinosaurs but also killed nearly 75 per cent of all species on the planet.

It may have also acidified Earth’s oceans after its impact, according to a study published in October 2019.

Another study published in September 2019 compared the impact of the asteroid to the power of 10 billion atomic bombs.

Researchers have uncovered several new species of dinosaurs in recent memory, including the world’s smallest dinosaur, a two-inch bird-like creature.

In early March, researchers published a study that suggested they have found traces of DNA inside a fossilized dinosaur skull.

Archaeology breakthrough: Second ‘hidden pyramid’ discovered inside iconic Mayan structure

Archaeology breakthrough: Second ‘hidden pyramid’ discovered inside iconic Mayan structure

Archaeologists have confirmed that the massive Kukulkan pyramid in eastern Mexico – one of the most iconic pyramids in the world – was built like a Russian nesting doll, with the discovery of two smaller pyramids hidden within its walls.

The first of the hidden pyramids was discovered back in the 1930s, built within the walls of the colossal Kukulkan tomb. Now an even smaller pyramid has been found inside that one – and the discoveries might not stop there. 

“To make matters more complicated, the third Russian doll moving in may actually be one of a set of several small dolls rattling around inside the same shell.

Ancient Mayan pyramid in Chichen Itza

We just do not know,” anthropologist Geoffrey Braswell from the University of California, San Diego, who was not involved in the study, told The Associated Press. Built sometime between the 9th and 12th centuries, the Kukulkan pyramid is the centrepiece of the vast Chichen Itza complex in the Mexican state of Yucatán. 

Also known as El Castillo (meaning “the castle”), this colossal pyramid features 364 steps – one for every day of the year in the Maya calendar system – and stands 24 metres (79 feet) tall. A 6-metre-high (20-foot) temple sits on top of the pyramid and was dedicated to the featured serpent god, Kukulkan.

Back in 1931, archaeologists began investigating the insides of the pyramid, with suspicions that it could be hiding the remains of a much older version – something that was widely disbelieved at the time.

Over the course of the next five years, they discovered a room nicknamed the hall of offerings, containing a giant Chacmool statue, its nails, teeth, and eyes inlaid with mother of pearl.

They also found a room called the chamber of sacrifices, containing two carefully arranged rows of human bones, and an elaborate red jaguar statue, encrusted with 74 jade inlays for spots, and jade-studded eyes.

The researchers soon realised that there was a larger, much older pyramid hidden below and inside the Kukulkan pyramid, and it stands roughly 33 metres tall (108 feet).

Now, archaeologists have completed their latest investigation of that internal pyramid using a non-invasive imaging technique called tri-dimensional electric resistivity tomography, and report the discovery of a 10-metre-tall (33-foot) pyramid hidden inside the larger two.

At this stage, it’s not clear if this the same structure archaeologists detected back in the 1940s but couldn’t confirm – or something else entirely.

Oddly enough, it appears to have been built above a water-filled sinkhole called a cenote, which researchers detected under the Kukulkan pyramid just last year. 

It’s not clear if the Maya knew of the cenote themselves, but the fact that the pyramids were built directly on top of it, and that Kukulkan was a god of water (among other things), suggests that maybe they did.

“The structure that we have found, the new structure, is not completely in the centre of the Kukulkan pyramid. It is in the direction where the cenote is,” Rene Chavez Segura, from the National Autonomous University of Mexico, told CNN.

“This could either confirm or hypothesise that the Mayans when they built this structure that they knew of the existence of this cenote.”

According to Segura and his team, the smallest pyramid was likely built between 550 and 800 AD. The middle structure has between 800 and 1000 AD, while the outer one was finished between 1050 and 1300 AD.

The researchers are yet to publish their findings, so these dates and the pyramid’s structure will still need to be verified by independent teams, but it’s hoped that further investigations will continue, so we can figure out if there are even more pyramids hidden inside.

“If this could be investigated in the future, this structure would be significant, because it would speak to the first few periods of habitation of the site and would provide information about how the settlement developed,” Denisse Argote from Mexico’s National Institute of Anthropology and History told CNN.

Researchers Discover Fossils Of A Unique ‘Eagle Shark’ That Glided Through Seas About 93 Million Years Ago!

Researchers Discover Fossils Of A Unique ‘Eagle Shark’ That Glided Through Seas About 93 Million Years Ago!

The eagle shark was probably not as fearsome as its name suggests. The ancient shark, described on March 19 in the journal Science, was most likely a slow-moving filter feeder that looked like a cross between a standard shark and a manta ray.

Researchers Discover Fossils Of A Unique ‘Eagle Shark’ That Glided Through Seas About 93 Million Years Ago!
The eagle shark’s long, slender side fins are one of its “most striking features,” says first author Romain Vullo.

But the eagle shark lived about 95 million years ago, 30 million years before modern rays appeared in the ocean. The find has palaeontologists wondering if other ancient sharks took unusual shapes since many are known only by the teeth they left behind.

The eagle shark, or Aquilolomna milarcae, fossil has the opposite appearance: an entire skeleton, but no teeth were preserved that would have helped palaeontologists categorize it.

The researchers took signs from other aspects of its anatomy—like its broad head and wide, wing-like fins—to draw conclusions about the shark’s behaviour.

“As this shark probably fed on plankton, it didn’t need to go fast,” says Romain Vullo, first author of the new study and a palaeontologist at the Université de Rennes, to New Scientist’s Adam Vaughan. “Like modern manta rays, relatively slow swimming was enough to eat plankton.”

The eagle shark’s broad head, wide fins, and lack of dorsal and pelvic fins make it look like a combination of a manta ray and a modern shark

A quarry worker found the unusual shark fossil in the Vallecillo limestone quarry in 2012. The region in northeastern Mexico is a well-known repository of marine fossils like ammonites, fish and marine reptiles, according to a statement.

Local palaeontologist Margarito González González learned of the discovery and set to work carefully chipping away at the stone to reveal the fossil that was preserved within, Riley Black reports for National Geographic.

“My first thoughts on seeing the fossil were that this unique morphology is totally new and unknown among sharks,” says Vullo to National Geographic.

While its head and side fins are unusual, the eagle shark’s tail and tail fins resemble those of modern sharks. So the researchers suggest that the shark probably used its tail to propel itself forward and its long side fins for stabilization. Manta rays have a different strategy, flapping their wide side fins to propel themselves forward.

“One of the most striking features of Aquilolamna is that it has very long, slender pectoral [side] fins,” writes Vullo in an email to Laura Geggel at Live Science, “This makes the shark wider than long,” because it is just over six feet wide but only about 5.4 feet long.

The fossil didn’t show signs of a dorsal fin—the notorious sign of an approaching shark that sticks up above the water—or of pelvic fins, which are on the underside of the shark. It’s not yet clear whether the eagle shark lacked these fins, or if they just didn’t fossilize, per Live Science.

The biggest mystery surrounding the eagle shark comes from the lack of teeth in the fossil. Palaeontologists rely on sharks’ teeth to identify them and figure out their evolutionary relationship to other ancient sharks.

The eagle shark might have had tiny, pointed teeth like the basking shark and the megamouth—two modern filter-feeding sharks—or taken a different strategy.

“It is truly unfortunate that no teeth were preserved in the specimen that could have allowed researchers to determine the exact taxonomic affinity of the new shark,” says DePaul University paleobiologist Kenshu Shimada to National Geographic.

For now, the research team used the shape of the fossil’s vertebrae and the skeleton of its tail fin to classify it like a shark in the order Lamniformes, which includes filter-feeding sharks, mako sharks and the great white.

Future fossilized finds and analysis of the eagle shark’s anatomy could help scientists understand the strange shapes of sharks in the distant past.

“There are a lot of unusual features described by these authors, and I have some reservations about some of their interpretations,” says Humboldt State University palaeontologist Allison Bronson, who wasn’t involved in the study, to National Geographic. “Ao I would be excited to see further investigations of this new, remarkable fossil.”

Controversial cave discoveries suggest humans reached the Americas much earlier than thought

Controversial cave discoveries suggest humans reached the Americas much earlier than thought

Stone tools unearthed in a cave in Mexico indicate that humans could have lived in the area as early as about 33,000 years ago, researchers reported. That’s more than 10,000 years before humans are generally thought to have settled North America.

Archaeologists have unearthed what appear to be stone tools, including this one, in a cave in central Mexico that date as early as about 33,000 years ago.

This controversial discovery enters a new piece of evidence into the fierce debate about when and how the Americas were first populated.

“A paper like this one is really stirring up the pot,” says co-author Eske Willerslev, an evolutionary biologist at the University of Cambridge. It “will no doubt get a lot of arguments going.”

For decades, archaeologists thought the Americas’ first residents were the Clovis people — big game hunters known for their well-crafted spearpoints who crossed a land bridge from Asia to Alaska about 13,000 years ago. Recent, well-accepted archaeological discoveries suggest that North America’s first settlers actually arrived a few thousand years before the rise of the Clovis culture, by about 16,000 years ago, says Vance Holliday, an archaeologist at the University of Arizona in Tucson not involved in the new work.

If the new finds really are human tools, Holliday says, this would be the oldest evidence for a human-inhabited site anywhere in the Americas.

At Chiquihuite Cave in central Mexico, archaeologists unearthed what appear to be over 1,900 stone tools.

Using radiocarbon dating to determine the ages of charcoal, bone and other detritus surrounding the artefacts, the researchers determined that more than 200 of the tools were embedded in a layer of the earth as old as 33,150 to 31,400 years. Other artefacts were found in a layer as fresh as about 13,000 years old.

The tools, excavated from 2016 to 2017, do not resemble Clovis technology or any other stone tools found in the Americas, the researchers say.

This haul “has a lot of small blades and small flakes that were used for cutting,” says archaeologist Ciprian Ardelean of the Autonomous University of Zacatecas in Mexico.

His team also dug up squarish stone fragments that he suspects were used to make composite tools of some sort, assembled from pieces of rock stuck into wooden or bone shafts.

“People are going to disagree about whether this qualifies as evidence” of human activity, says Loren Davis, an archaeologist at Oregon State University in Corvallis not involved in the work. “These are rocks that were broken, but … people don’t have a monopoly on the physics involved with breaking rocks,” Davis says that a closer examination of the artefacts in person or via 3-D models could convince him that they are indeed relics of human craftsmanship.

Ben Potter, an archaeologist in Fairbanks, Alaska, affiliated with the Arctic Studies Center at Liaocheng University in China, is similarly “intrigued but unconvinced” that Chiquihuite Cave was an ancient human abode. He notes the crude shape of many of the artefacts, as well as the absence of other evidence — such as butchered animal remains or human DNA — that would peg the site as a human residence.

Humans may have arrived in North America way earlier than archaeologists thought
Researchers looking for ancient DNA take samples in Chiquihuite Cave, Mexico.

Neither the tools’ shape nor the apparent lack of other human-made remains disqualifies Chiquihuite Cave as an ancient dwelling, Ardelean says. He argues that archaeologists’ expectations of what North American stone tools should look like are overly influenced by the perfection of Clovis points, which were neatly chipped from brittle stone such as jasper. The limestone used by the Chiquihuite Cave dwellers was more difficult to work with, he says, so it makes sense that these implements would be more rugged.

As for corroborating evidence of human activity, Ardelean expects human DNA to turn up only in specific areas of the cave, like where people ate or relieved themselves. He and his colleagues may not have excavated those spots yet, he says. The swath of ground investigated in this dig was also far from the mouth of the cave, where ancient people would more likely have cooked, eaten, thrown out garbage and performed other daily activities, he says.

Anthropologist Ruth Gruhn of the University of Alberta in Edmonton “wasn’t a bit surprised” at the authors’ claim of 30,000-year-old human handiwork in Mexico.

This cave joins a handful of sites in Brazil that have shown evidence of human occupation more than 20,000 years ago — although those reports remain controversial. To convince many archaeologists that humans really were in the Americas so early, “what you need is an accumulation of sites of that antiquity,” says Gruhn, whose commentary on the new study appears in Nature.

If there were humans in Mexico more than 30,000 years ago, that would affect what route they could have taken south from Alaska, says geologist Alia Lesnek of the University of New Hampshire in Durham. Archaeologists have thought that if humans arrived about 16,000 years ago, they may have plodded south along the Pacific Coast.

That’s because a narrow, inland ice-free corridor between two ice sheets covering Canada would not have had enough plants or animals to sustain human travellers. But more than 30,000 years ago, those ice sheets had not yet reached their full extent, Lesnek says, opening up the possibility of inland migration.