Possible Prehistoric Campsite Uncovered in Northern Wyoming

Artefacts found this summer at Medicine Lodge Archaeological Site are slated for radiocarbon dating, which could tell researchers more about when the Crow, or Apsáalooke, people came to the area, according to the Wyoming State Archaeologist.

“This summer, we found Crow ceramics, as well a range of things, from thousands and thousands of flakes and 10 arrow points (or arrowheads), and preforms to make arrowheads, to animal bone from bison as well as bighorn sheep, as well as obsidian,” Wyoming State Archaeologist Spencer Pelton said.

“We really hoped to find Crow ceramics to radiocarbon date, to have a better idea of how old those ceramics are,” he said.

Sharon Peregoy, a member of the Montana House of Representatives who represents the Crow Agency, said that this type of work may help date, early people of the area, preserving — or recovering — a history that can otherwise be lost.

“It helps dispel the concept that the Crow, Apsáalooke, people were new transplants to the area,” she said, adding that in this context, “new” means the arrival of 500 years ago.

“The findings of these types of excavations and research correlates with our Crow oral history, which dates from time immemorial. … Prehistoric,” Peregoy said. “History is important to preserve a homeland for future generations.”

The Office of the Wyoming State Archaeologist is currently doing a ceramics research project, and had hoped to find similar material at Medicine Lodge during its first-ever “public excavation” this summer, Pelton said. The area that is now Medicine Lodge State Archaeological Site has been continuously occupied for more than 10,000 years, according to Wyoming State Parks. In the 1880s it was a working cattle ranch. In 1972, it was purchased by the Wyoming Game and Fish Department, which created the 12,000-acre Medicine Lodge Wildlife Habitat Management Area.

In 1973, a portion of the habitat management area was developed into Medicine Lodge State Archaeological Site. Today, visitors can camp along Medicine Lodge Creek, which flows through a canyon that offers respite in the summer from the hot, dry desert, and warmth and shelter in the winter.

“This spot was undoubtedly a campsite for a long time,” Pelton said. “It’s such an oasis down there, with fresh water. It probably stays fairly warm in the winter from the heat radiating off of the cliffs, and then relatively cool in the summer.

“I know it stays relatively cool in the summer because the moment you climb out of that canyon the temperature increases by 15 degrees,” he said of his experience at the excavation this summer. Because Medicine Lodge is a high-traffic area, and one accessible to the public, it was the ideal place to engage the public with the research.

“We encouraged people to stop by and take a look at what we were doing, maybe screen some dirt,” he said, adding that around 600 people stopped over the summer.

“It turned out really great, and in the process we got some legitimate research done as well,” Pelton said.

The rock art in the valley dates back 10,000 years, and includes petroglyphs and painted rock-art images, or pictographs. The rock art covers the face of a 750-foot-long sandstone bluff, which shelters the area at its base from the wind.

“The rock art certainly includes Crow art,” Pelton said. “When you look at modern Crow art, and look at Crow mythology, you can see a lot of the same motifs on the rock art and cliffs from around A.D. 1400, 1600. A lot of those traditions are still around today.”

Other rock art at Medicine Lodge likely predates the Crow people, he said.

“That is the amazing thing about Medicine Lodge. People probably came and made rock art there for thousands and thousands of years, and we still see the last couple thousand years of it today,” Pelton said. “People were making images on top of each other over and over again.”

Previous excavations done in the 1970s revealed an early presence in the valley.

“It was thought to be an archaeological site created by the ancestors of the Crow,” Pelton said. “(Early researchers) knew that from portions of a ceramic vessel they found there, the rim of a pot.”

Finding ceramics like that is rare in Wyoming, but also valuable as one of the best artefacts for determining ancestry.

“These things are really distinct, and you can track them across time and space to see how those different finds change through time,” Pelton explained. “Our first research priority is getting some radiocarbon dates on some charcoal, and maybe animal bone, with some of those ceramics.”

Another thing found this summer during the public excavation was obsidian, which almost certainly came from the Crow component at Medicine Lodge.

“Obsidian is distinct from all the preceding 12,000 years of prehistory at Medicine Lodge Creek,” he said. “The great thing about obsidian is that you can source it precisely to specific outcrops, so we will know now where these people carrying Crow-style pottery into Medicine Lodge Creek came from. It is probably somewhere in Yellowstone, it could be Teton Pass or it could be all the way over in Idaho.”

Pelton said his office will likely do another public excavation in the summer of 2022. The key is finding a site that is accessible to the public and safe for people to gather.

“The tricky part is finding that perfect confluence of places that are publicly accessible that also have a cool archaeological site buried underneath it,” Pelton said, adding that the tentative plan is to do a similar event at Edness Kimball Wilkins Park in Natrona County. He hopes to reach people there who may not otherwise know about Wyoming’s archaeological past.

“There are some really well-known, easily accessible archaeological sites in that park, and that place gets a lot of visitation,” Pelton said. “We can start reaching a whole other demographic of people who are not normally exposed to this kind of thing, and expand our education and outreach opportunities.”

New evidence supports idea that America’s first civilization was made up of ‘sophisticated’ engineers

The Native Americans who occupied the area known as Poverty Point in northern Louisiana more than 3,000 years ago long have been believed to be simple hunters and gatherers. But new Washington University in St. Louis archaeological findings paint a drastically different picture of America’s first civilization.

Far from the simplicity of life sometimes portrayed in anthropology books, these early Indigenous people were highly skilled engineers capable of building massive earthen structures in a matter of months — possibly even weeks — that withstood the test of times, the findings show.

“We as a research community — and population as a whole — have undervalued native people and their ability to do this work and to do it quickly in the ways they did,” said Tristram R. “T.R.” Kidder, lead author and the Edward S. and Tedi Macias Professor of Anthropology in Arts & Sciences.

“One of the most remarkable things is that these earthworks have held together for more than 3,000 years with no failure or major erosion.

By comparison, modern bridges, highways and dams fail with amazing regularity because building things out of the dirt is more complicated than you would think. They really were incredible engineers with very sophisticated technical knowledge.”

The findings were published in Southeastern Archaeology on September 1, 2021. Washington University’s Kai Su, Seth B. Grooms, along with graduates Edward R. Henry (Colorado State) and Kelly Ervin (USDA Natural Resources Conservation Service) also contributed to the paper.

The Poverty Point World Heritage site consists of a massive 72-foot-tall earthen mound and concentric half-circle ridges. The structures were constructed by hunter-gatherers approximately 3,400 years ago from nearly 2 million cubic yards of soil.

Amazingly, this was done without the luxury of modern tools, domesticated animals or even wheeled carts.

According to Kidder, the site was likely an important religious site where Native Americans came in pilgrimage, similar to Mecca. It was abandoned abruptly between 3,000-3,200 years ago — most likely due to documented flooding in the Mississippi Valley and climate change.

The ridges at Poverty Point contain vast amounts of artefacts around the edges and within, suggesting that people lived there. Kidder and the team re-excavated and re-evaluated a site on Ridge West 3 at the Poverty Point Site that was originally excavated by renowned archaeologist Jon Gibson in 1991.

Using modern research methods including radiocarbon dating, microscopic analysis of soils and magnetic measurements of soils, the research provides conclusive evidence that the earthworks were built rapidly. Essentially, there is no evidence of boundaries or signs of weathering between the various levels, which would have occurred if there was even a brief pause in construction. Kidder believes the construction was completed in lifts, or layers of sediment deposited to increase the ridge height and linear dimensions before another layer were placed to expand the footprint vertically and horizontally.

Why does that matter? According to Kidder, the findings challenge previous beliefs about how pre-modern hunters and gatherers behaved. Building the enormous mounds and ridges at Poverty Point would have required a large labour pool that was well organized and would have required leadership to execute. Hunters and gathers were believed to shun politics.

“Between the speed of the excavation and construction, and the quantity of earth being moved, these data show us native people coming to the site and working in concert. This in and of itself is remarkable because hunter-gatherers aren’t supposed to be able to do these activities,” Kidder said.

What’s even more impressive than how quickly the people built the earthen structures is the fact that they’re still intact. Due to its proximity to the Gulf of Mexico, this area receives immense amounts of rain that makes earthworks especially prone to erosion. Microscopic analysis of soils shows that the Native Americans mixed different types of soil — clays, silts and sand — in a calculated recipe to make the structures stronger.

“Similar to the Roman concrete or rammed earth in China, Native Americans discovered sophisticated ways of mixing different types of materials to make them virtually indestructible, despite not being compacted. There’s some magic there that our modern engineers have not been able to figure out yet,” Kidder said.

Ancient humans could do some impressive things with elephant bones

In a new study, University of Colorado Boulder archaeologist Paola Villa and her colleagues surveyed tools excavated from a site in Italy where large numbers of elephants had died. The team discovered that humans at this site roughly 400,000 years ago appropriated those carcasses to produce an unprecedented array of bone tools—some crafted with sophisticated methods that wouldn’t become common for another 100,000 years. 

“We see other sites with bone tools at this time,” said Villa, an adjoint curator at the CU Boulder Museum of Natural History. “But there isn’t this variety of well-defined shapes.”

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Villa and her colleagues published their results this month in the journal PLOS ONE.

The study zeroes in on a site called Castel di Guido not far from modern-day Rome. Hundreds of thousands of years ago, it was the location of a gully that had been carved by an ephemeral stream—an environment where 13-foot-tall creatures called straight-tusked elephants (Palaeoloxodon antiquus) quenched their thirst and, occasionally, died. 

Castel di Guido’s hominids made good use of the remains, occupying the site off and on over the years. The researchers report that these Stone Age residents produced tools using a systematic, standardized approach, a bit like a single individual working on a primitive assembly line. 

“At Castel di Guido, humans were breaking the long bones of the elephants in a standardized manner and producing standardized blanks to make bone tools,” Villa said. “This kind of aptitude didn’t become common until much later.”

Stone Age toolbox

These feats of ingenuity came at a significant time for hominids in general.

Right around 400,000 years ago, Neanderthals (Homo neanderthalensis) were just beginning to emerge in Europe. Villa suspects that Castel di Guido’s residents were Neanderthals. 

“About 400,000 years ago, you start to see the habitual use of fire, and it’s the beginning of the Neanderthal lineage,” Villa said. “This is a very important period for Castel di Guido.”

It may have been a productive one, too. In their new study, Villa and her colleagues identified 98 bone tools from Castel di Guido, which was excavated from 1979 to 1991. The findings represent the highest number of flaked bone tools made by pre-modern hominids that researchers have described so far. That rich toolbox offered a wide range of useful items: Some tools were pointed and could, theoretically, have been used to cut meat. Others were wedges that may have been helpful for splitting heavy elephant femurs and other long bones. 

“First you make a groove where you can insert these heavy pieces that have a cutting edge,” Villa said. “Then you hammer it, and at some point, the bone will break.”

But one tool stood out from the rest: The team discovered a single artifact carved from a wild cattle bone that was long and smooth at one end. It resembles what archaeologists call a “lissoir,” or a smoother, a type of tool that hominids used to treat leather. The curious thing: Lissoir tools didn’t become common until about 300,000 years ago.

“At other sites 400,000 years ago, people were just using whatever bone fragments they had available,” Villa said.

Useful finds

Something special, in other words, seemed to be happening at the Italian site. 

Villa doesn’t think that the Castel di Guido hominids were any more intelligent than their counterparts elsewhere in Europe. Instead, these early humans simply used the resources they had lying around. She explained that this region of Italy doesn’t have a lot of naturally occurring, large pieces of flint, so ancient humans couldn’t make many large stone tools. 

What the region might have had a lot of, however, were dead elephants. As the Stone Age progressed, straight-tusked elephants slowly disappeared from Europe. During the era of Castel di Guido’s bone-crafters, these animals may have flocked to watering holes at the site, occasionally dying from natural causes. Humans then found the remains and butchered them for their long bones. 

“The Castel di Guido people had cognitive intellects that allowed them to produce complex bone technology,” Villa said. “At other assemblages, there were enough bones for people to make a few pieces, but not enough to begin a standardized and systematic production of bone tools.”

Mystery of the “East Bay” rock walls in California?

There are Remnants of Ancient stone walls all over the East Bay, and no one knows how old they are, who built them, or why?

Though people have been pondering the enigma of the  Berkeley Mystery Walls for well over a hundred years, no conclusions have been reached, and despite wild speculation, no serious scholarly study has ever been undertaken.

Stretching for over 50 miles, the East Bay “Mystery Walls” are found up and down the hills of the East Bay from Berkeley to San Jose.

The stone walls are up to five feet tall in places and are constructed from boulders of varying sizes, some weighing up to a ton.

The walls run in broken sections, anywhere from a few meters to half a mile in length, and are placed in unlikely and inaccessible places. They seem to serve no known purpose.

They are not continuous or high enough to act as an enclosure, or measure of defence. They are clearly, visibly, very old.

The heavy stones have sunk deep into the ground, and they are overgrown with lichen. After meandering throughout the Oakland hills, they head inland towards Mt. Diablo where they lead to mysterious stone circles, up to 30 feet in diameter. In one place the walls form a spiral 200 feet wide that circles a large boulder.

The Spanish settlers in the area reported that the walls were already there when they arrived, and when they asked the local Ohlone American Indians, they said the same thing.

In 1904, the founder of the Contra Costa Club said the walls were clearly of prehistoric origin and could be evidence that an advanced civilization had once settled in the East Bay.

Also in 1904, the professor of Oriental languages at UC Berkeley declared that the walls were surely the work of settlers from Mongolia, as the Chinese tended to wall in their cities, and the mystery walls were reminiscent of the Great Wall of China.

Others have theorized that they were built by the early Missionaries, and still, others wonder if Sir Frances Drake did not leave colonists behind at the site where he completed the circumnavigation of the globe.

While speculations abound, the “Mystery Walls of the East Bay,” or the “Great Wall of California” remains a mystery to this day.

The insect, which is 49 million years old, appears to have been smashed just a few days ago

A beetle that lived about 49 million years ago is so well-preserved that the insect looks like it could spread its strikingly patterned wing coverings and fly away. That is if it weren’t squashed and fossilized. 

Wing cases, or elytra, are one of the sturdiest parts of a beetle’s exoskeleton, but even so, this level of colour contrast and clarity in a fossil is exceptionally rare, scientists recently reported. 

The beautiful design on the ancient beetle’s elytra prompted researchers to name it Pulchritudo attenboroughi, or Attenborough’s Beauty, after famed naturalist and television host Sir David Attenborough. They wrote in a new study that the pattern is “the most perfectly preserved pigment-based colouration known in fossil beetles.”

When the researchers described the beetle beauty, it was already in the collection of the Denver Museum of Nature and Science (DMNS) in Colorado, where it had been on display since it was identified in 1995.

Palaeontologists found the fossil that year in the Green River Formation; once a group of lakes, this rich fossil site spans Colorado, Wyoming and Utah, and dates to the Eocene epoch (55.8 million to 33.9 million years ago). 

Scientists initially classified the fossil as a long-horned beetle in the Cerambycidae genus. But while its body shape resembled those of long-horned beetles, its hind limbs were unusually short and beefy, which led the museum’s senior curator of entomology — Frank-Thorsten Krell, lead author of the new study — to question if the beetle might belong to a different group. 

In the study, the authors described the beetle as a new genus in a subfamily known for its robust and powerful hind legs: frog-legged leaf beetles.

The fossilized insect, a female, is only the second example of a  frog-legged leaf beetle to be found in North America, Krell told Live Science in an email (no modern beetles in this group live in North America today, according to the study).

On P. attenboroughi’s back, dark and symmetrical circular patterns stand out in sharp contrast against a light background. This suggests that bold patterns were present in beetles at least 50 million years ago, the researchers reported. 

For a beetle to fossilize as well as this one did, “you need a very fine-grained sediment,” Krell said. Silt or clay at the bottom of a lake is the best substrate for fossilizing insects, and the beetle must sink quickly into the silty lake bottom before its body disintegrates. “And then it should not rot, so an oxygen-poor environment on the lake floor is helpful,” he said. 

However, questions still remain about how sediments in the lake bottom preserved the beetle’s high-contrast colours so vividly, Krell added.

Visitors to the DMNS can admire P. attenboroughi for themselves, as the renamed fossil is back on display in the museum’s “Prehistoric Journey” exhibit, representatives said in a statement.

6,000-Year-Old Axe Discovered at George Washington’s Estate

About 6,000 years ago, a precious stone axe that had been skillfully carved and shaped by Native Americans was lost on a ridge overlooking the Potomac River in Virginia. The axe, about seven inches long, had been hewed and smoothed and was narrowed at one end where a wooden handle attached. Its loss must have been keenly felt.

Six millennia later, on Oct. 12, 2018, Dominic Anderson and Jared Phillips, 17-year-hold high school seniors from Ohio, were on an archaeological dig at George Washington’s estate at Mount Vernon, when a stone that looked like a big potato turned up in their sifting screen. Not sure what it was, they asked the Mount Vernon archaeologists working nearby.

It was the lost axe, missing for 60 centuries.

Officials at Mount Vernon announced details of the find. They said it was a major discovery that helps take the story of the site far beyond its place as the home of the first president of what would become the United States.

It “provides a window onto the lives of individuals who lived here nearly 6,000 years ago,” said Sean Devlin, Mount Vernon’s curator of archaeological collections. “Artifacts such as this are a vital resource for helping us learn about the diverse communities who shaped this landscape throughout its long history.”

Mount Vernon officials said the axe had been made from a piece of “greenstone” probably taken from a local river. It had been chipped with a hammer stone to create a cutting edge and then further carved with a harder stone to create a smoother cutting surface. It was then worked even further with a grinding stone, and the groove was cut where the handle would attach. The tool was probably highly valuable.

Devlin said the axe was dated through knowledge of when such tools came into use, by comparing it to other tools from the period, and by dating the methods of its construction. It is believed to be the first such artefact found at Mount Vernon in recent years.

The makers of the axe were probably people who migrated by boat up and down the Potomac River seasonally and may not have lived in fixed villages, Devlin said in a telephone interview. The axe would have been a key possession during their travels.

“When you spend the effort to make tools like this axe, you would have probably carried it with you,” he said. “You wouldn’t just make something like this off the cuff . . . and used it once or twice and chucked it. . . . This is something people invested time in. It definitely isn’t something that was just sort of pitched by the side, just by happenstance.”

The axe was probably used for cutting or carving wood, he said. It probably was not a weapon.

“It’s always fantastic to go out there and see something that’s so evocative,” he said.

The axe was found by students from Archbishop Hoban High School, in Akron, Ohio. Fourteen students, headed by archaeology teacher Jason Anderson, were helping to map out the dimensions of what is believed to be a cemetery for Mount Vernon’s enslaved African Americans and their descendants.

But the area is relatively pristine and has many prehistoric artefacts, said Joe Downer, Mount Vernon’s archaeological field research manager. Downer said Dominic Anderson, the teacher’s son, and Phillips, the second student, called out to him when they found the axe.

“Is this anything?” Downer said they asked.

“I was kind of taken aback when I saw it,” he said in a telephone interview. “I looked at it, and I held it for a minute, and I was like, ‘Well, that might be one of the coolest things we found out here.’ “

“It’s pretty unmistakable when you see it,” he said.

Jason Anderson, the teacher, said the school’s students have been doing archaeology work at Mount Vernon for six years.

“It’s not a field trip,” he said in a telephone interview. “The students are working. This isn’t just kind of kickback . . . and have a fun time. It’s a lot of work, but it’s very fulfilling work.”

“The neatest thing is: The whole purpose we do any of this stuff is to get students interested in archaeology,” he said. “I’m really glad I didn’t find it, or any of the adults found it. I was super, super excited when the students were the ones to sift through it and say, ‘Hey, what is this?’

German Museum Returns Native American Leader’s Shirt

With German institutions placing a renewed emphasis on the repatriation of various objects in their holdings, the Weltkulturen Museum in Frankfurt said this week that it had given the leather shirt of Chief Daniel Hollow Horn Bear (Mato He Oklogeca), of the Teton Lakota, to his great-grandson Chief Duane Hollow Horn Bear. In a press release, the museum cited “moral and ethical reasons” for the return.

The leather shirt was handed over to Duane Hollow Horn Bear on June 12 in Rosebud, South Dakota. Duane Hollow Horn Bear had visited the Weltkulturen Museum in 2019 and submitted a request for the shirt’s return that included a historic portrait photograph, dated to 1900, by John Alvin Anderson.

The picture showed Chief Daniel Hollow Horn Bear, who died in 1913, wearing the shirt. Chief Daniel Hollow Horn Bear was a well-respected leader and politician who advocated for the rights of his people and was often a chief negotiator with the U.S. government.

In 2019, when he requested the shirt’s return, Chief Duane Hollow Horn Bear said in a video documenting the repatriation process, “It’s been a hard journey just to come here today. I’m humbled not just to see [his shirt] in a picture, but to hold it in my hand like I’m holding his hand. . . . Grandpa come home. We need you.”

In a statement, the Weltkulturen Museum said, “The Chief’s shirt is a culturally specific, identity-forming object of religious significance to the Teton Lakota Indigenous community.

It bears special patterns of brightly coloured glass beads and human hair, which are undoubtedly attributable to the Hollow Horn Bear family and prove personal possession prior to 1906.

For Chief Duane Hollow Horn Bear and his family, the return of the shirt is like the return of the great-grandfather himself.”

The Weltkulturen Museum came into possession of the shirt in 1908 through an exchange with the American Museum of Natural History in New York.

For the past 30 years, the shirt had been on permanent loan and display to the German Leather Museum in the nearby town of Offenbach.

The AMNH had received the shirt only two years earlier as part of a larger donation by James Graham Phelps Stokes, a New York millionaire and philanthropist whose family’s wealth came from the Phelps-Dodge Company.

In its release announcing the shirt’s repatriation, the Weltkulturen Museum said, “The circumstances under which the shirt previously came into the possession of J.G. Phelps could not be reconstructed.”

In a statement, Ina Hartwig, deputy mayor in charge of Culture and Science for the City of Frankfurt am Main, said “Provenance research is one of the great challenges facing museums in the 21st century.

The Frankfurt museum landscape has been taking this challenge very seriously for years and is subjecting its collections to a systematic revision.

Even if it represents a loss for the collection and the object was legally acquired by the Weltkulturen Museum: I see the return of the leather shirt to Chief Duane Hollow Horn Bear as an obligation that outweighs the formal legal situation.”

Humans Lived in North America 130,000 Years Ago, Study Claims

Three years ago, a team of archaeologists in the United States proposed an extraordinary idea: the first human settlers in the Americas arrived at least 100,000 years earlier than we thought.

The evidence came from a collection of mastodon bones and ancient stones dating back to around 130,000 years ago, which appeared to have been hammered and scraped by early humans. 

The remains were found in the suburbs of San Diego in the 1990s, and the researchers think that the nearby stones may have been used as hammers and anvils to work on the bones. But outside of that, no other traces of human activity were found.

Today, the Cerutti Mastodon (CM) site remains one of the most controversial archaeological digs in the world. For years, scientists have been going back and forth over the results and whether or not they indicate the presence of humans in North America 130,000 years ago, but the original authors are not giving up. 

The team has now published a follow-up paper that claims to have found traces of ancient mastodon bones on the upward-facing sides of two cobblestones collected from the site.  According to the paper, mastodon bones were indeed placed on top of these rocky ‘anvils’ and struck with some sort of hammer – presumably by humans. If the bones were merely in passive contact with the rocks, you would expect to see their influence everywhere they were touching, not just the top part. 

There also doesn’t appear to be any modern contamination, the authors add. The ancient artefacts were found near a road work site, so some critics think the bones were broken and scraped by the activity of trucks and other similar disturbances.

While this is very much possible, researchers say it doesn’t explain the residue on the stones. When collecting bones and stones from the site, the team in San Diego claims to have taken great care. They say there was no opportunity for bone material to disintegrate or “float” into the air and onto a stone at the original site or in the lab afterwards.

Even in the soil, bone residues from these mastodons were discovered at much lower concentrations than what was measured on some parts of the cobblestones.

“Fossil bone residues documented with the Raman microscope were only found in residue extractions sampled from the potentially used surfaces and are therefore considered to be more likely use-related,” the authors write.

“As our investigations have indicated that the bone residues are less likely to originate from sediments or contact with bones in the bone bed as discussed above, the most parsimonious explanation is that the residues (and wear) derive from deliberate contact with bone. We consider this scenario to be the most likely.” 

Still, there is one key missing ingredient: collagen. This is an important part of mammal bones, and if stones were used to break apart the mastodon skeleton, you’d expect to find some traces of collagen.

It’s very possible that the collagen in this case had already disintegrated from the passing of time. Or it could be that measurements simply didn’t pick up on its presence. But archaeologist Gary Haynes, who was not involved in the study, told Science News he thinks the more likely scenario is that road work vehicles buried these stones next to the mastodon bones, long after their collagen had disappeared.

He’s not the only one who’s sceptical. Today, most evidence suggests human settlers arrived in the Americas roughly 14,000 to 20,000 years ago. A date of 130,000 years is quite the claim, and it requires extraordinary evidence, which some scientists argue is lacking. A rebuttal to the original 2017 paper argued that other processes outside of human hammering produced bone damage, especially from heavy construction equipment.

Even before humans came along there was probably disturbance in the area. Over time, as fluvial deposits slowly covered the remains, these mastodon bones would have remained somewhat flexible, and this means they could have been trampled, displaced, fractured, abraded and reoriented by other mammals that used the ancient muddy watercourse.

“The extraordinary claim by Holen et al. of prehistoric hominin involvement at the CM site should not be contingent on evidence that is open to multiple, contrasting interpretations,” the authors of the rebuttal argue.

“Until unambiguous evidence of hominin activities can be presented, such as formal stone tools or an abundance of percussion pits, caution requires us to set aside the claims of Holen et al. of prehistoric hominin activities at the CM site.”

Shortly afterwards, the original authors wrote a rebuttal to the rebuttal. In it, they argued that there is no evidence of fluvial deposits and that the bones were broken before they were buried and not trampled afterwards.

“Healthy scepticism is the foundation of good science, and the publication of this discovery is the beginning of a scientific debate, which I welcome and encourage,”  Tom Deméré, a palaeontologist at the San Diego Natural History Museum and one of the original authors, argued a few years ago.

“What I didn’t expect was the reluctance of scientists to engage in a two-way conversation to objectively evaluate our hypothesis.” 

Archaeologist David Meltzer from Southern Methodist University is sceptical but open to the debate. He says he could be convinced that humans arrived in the Americas 100,000 years earlier than we thought, but that he hasn’t seen enough evidence yet. 

“Given everything we know, it makes no sense,” he told Nature in 2018. “You’re not going to flip people’s opinion 180 degrees unless you’ve got absolutely unimpeachable evidence, and this ain’t it.”

Perhaps this new bout of evidence will help clear up some of that doubt. More likely than not, however, it will merely trigger a series of new rebuttals.