What it is: A cerulean statuette of a hippopotamus molded in faience, a glazed ceramic material made partly out of ground quartz. The artifact is decorated with drawings of lotus flowers, which grow in marshes and symbolize regeneration and rebirth.

Where it was found: Inside a shaft associated with a tomb chapel in Meir, an ancient Egyptian cemetery located outside the city of Asyut. 

When it was made: Circa 1961 to 1878 B.C.

What it tells us about the past: Ancient Egyptians feared hippos (Hippopotamus amphibius), viewing them as dangerous and aggressive animals, especially when provoked, according to The Metropolitan Museum of Art in New York City. Thanks to these mostly herbivorous mammals' insatiable appetites, they often wreaked havoc on farmers' fields. In fact, one papyrus refers to a particularly bad harvest in which "the worm took half and the hippopotamus ate the rest."

Related: The Hope Diamond: The 'cursed' blue gemstone coveted by royalty

Hippo hunts were a common sport among the ancient Egyptians, who would use harpoons to snare the large beasts, which were associated with chaos. By 3000 B.C., depictions of kings successfully battling hippos became commonplace, as it was a way to show rulers overcoming chaos. However, due to overhunting, the last wild hippos disappeared from Egypt by the early 19th century, according to The Met.

This statuette, which measures about 8 inches by 5 inches (20 centimeters by 11 cm), is one of many examples of hippo sculptures crafted by ancient Egyptians. When it was discovered, three of its legs were missing and were likely broken on purpose to prevent it from doing harm in the afterlife, according to The Met.

In 1931, the artifact was dubbed "William" after the British humor magazine Punch ran a cartoon about the hippo.

These kinds of food mysteries are pretty hard to solve. Archaeology depends on solid remains to figure out what happened in the past, especially for people who didn't use any sort of writing. Unfortunately, most stuff people traditionally used made from wood, animal materials or cloth decays pretty quickly, and archaeologists like me never find it.

We have lots of evidence of hard stuff, such as pottery and stone tools, but softer things — such as leftovers from a meal — are much harder to find. Sometimes we get lucky, if softer stuff is found in very dry places that preserve it. Also, if stuff gets burned, it can last a very long time.

Related: Who invented bread?

Corn's ancestors

Luckily, corn — also called maize — has some hard parts, such as the kernel shell. They're the bits at the bottom of the popcorn bowl that get caught in your teeth. And since you have to heat maize to make it edible, sometimes it got burned, and archaeologists find evidence that way. Most interesting of all, some plants, including maize, contain tiny, rock-like fragments called phytoliths that can last for thousands of years.

Scientists are pretty sure they know how old maize is. We know maize was probably first farmed by Native Americans in what is now Mexico. Early farmers there domesticated maize from a kind of grass called teosinte.

Before farming, people would gather wild teosinte and eat the seeds, which contained a lot of starch, a carbohydrate like you'd find in bread or pasta. They would pick teosinte with the largest seeds and eventually started weeding and planting it. Over time, the wild plant developed into something like what we call maize today. You can tell maize from teosinte by its larger kernels.

There’s evidence of maize farming from dry caves in Mexico as early as 9,000 years ago. From there, maize farming spread throughout North and South America.

Popped corn, preserved food

Figuring out when people started making popcorn is harder. There are several types of maize, most of which will pop if heated, but one variety, actually called "popcorn," makes the best popcorn. Scientists have discovered phytoliths from Peru, as well as burned kernels, of this type of "poppable" maize from as early as 6,700 years ago.

You can imagine that popping maize kernels was first discovered by accident. Some maize probably fell into a cooking fire, and whoever was nearby figured out that this was a handy new way of preparing the food. Popped maize would last a long time and was easy to make.

Ancient popcorn was probably not much like the snack you might munch at the movie theater today. There was probably no salt and definitely no butter, since there were no cows to milk in the Americas yet. It probably wasn't served hot and was likely pretty chewy compared with the version you're used to today.

It's impossible to know exactly why or how popcorn was invented, but I would guess it was a clever way to preserve the edible starch in corn by getting rid of the little bit of water inside each kernel that would make it more susceptible to spoiling. It's the heated water in the kernel escaping as steam that makes popcorn pop. The popped corn could then last a long time. What you may consider a tasty snack today probably started as a useful way of preserving and storing food.

This edited article is republished from The Conversation under a Creative Commons license. Read the original article.

A team of archaeologists, conservators and volunteers from Time Team, the U.K.'s National Trust and FAS Heritage discovered the metal fragments in late June during excavation and metal-detecting work at Sutton Hoo.

Sutton Hoo is best known for its magnificent seventh-century ship burial, whose 1939 discovery was featured in the 2021 movie "The Dig." But the burial was just one part of a complex of 18 separate burial mounds found near Suffolk in southeastern England, many of which contained jewelry and coins. Evidence of imported goods — including an Egyptian bowl, Eastern Mediterranean silverware and a Middle Eastern petroleum product called bitumen — has also been discovered at Sutton Hoo.

But the copper-alloy bucket, known as the Bromeswell Bucket, predates the ship burial by at least a century. The fragmented bucket, which was found in 1986, depicts a North African hunting scene featuring lions and a dog. It was likely produced in the sixth century in Antioch, Turkey, which was then part of the Byzantine Empire. An inscription in Greek on the bucket reads, "Use this in good health, Master Count, for many happy years," suggesting that it may have been a diplomatic gift.

Related: Metal detectorist finds sword pyramid from time of mysterious Sutton Hoo burial

The artifacts uncovered last month were decorated with figures similar to those on the original find. So the team employed X-ray fluorescence (XRF) — which is used to determine which elements are present in an object and to create a unique elemental "fingerprint" of the artifact — to confirm that the newly recovered fragments are indeed part of the sixth-century Bromeswell Bucket. 

"Thanks to closer inspection, we now believe that the bucket had been previously damaged and then repaired," Angus Wainwright, a regional archaeologist in the East of England for the National Trust, said in a statement. "In-depth analysis of the metals suggests it might even have been soldered back together."

Although East Anglia has been occupied since at least 3000 B.C., when Sutton Hoo was in use as a cemetery in the sixth and seventh centuries, the area was relatively densely populated and part of a busy trade network. The Sutton Hoo treasures represent diverse objects, including pagan and Christian artifacts, brought there from all over Europe and the Middle East. The ship burial and cosmopolitan nature of Sutton Hoo may even link it to the Old English epic poem Beowulf, which includes tales of gift-bestowing kings from far-flung lands and was composed around the same time.  

"It's hoped that this two-year research project will help us learn more about the wider landscape at Sutton Hoo and the everyday lives of the people that lived there," Wainwright said. "So, this find is a great step on that journey." 

The burial mound, known as a barrow, is roughly 620 feet (190 m) long — nearly twice the length of an American football field — about 50 feet (15 m) across at its widest point, and oriented along a northeast-to-southwest axis, according to a translated statement from the University of Hradec Králové (UHK). 

The archaeologists think it dates from the fourth millennium B.C., which would make it one of the earliest funeral monuments ever found in Europe.

The date corresponds with the Funnel-Beaker people who lived in the area between 3800 and 3350 B.C. They are named after the distinctive pottery vessels given as grave goods in many of their burials.

The barrow "represents the longest prehistoric mound not only in our region, but probably in the whole of Europe," Petr Krištuf, an archaeologist at the UHK, said in the statement.

Related: 'Jackpot' of 2,000 early-medieval coins discovered by hiker in Czech Republic

In addition to the two central burials in the barrow, which were probably those of high-status members of the prehistoric community that built it, about 30 graves thought to date from around the same time have been located nearby, according to a translated Facebook post from the department.

Highway discovery

The barrow was found during archaeological excavations beside a highway route between the city of Hradec Králové and the village of Sadová, about 55 miles (88 kilometers) east of Prague. 

The burial mound was no longer visible on the surface because it was located in a heavily farmed area that had been leveled at some point, according to the Facebook post.

As a result, the archaeologists first found buried evidence of the trench that surrounded the burial mound. Similar trenches around other barrows in the area contained postholes from a wooden palisade, but such evidence has not been found at this location, the Facebook post said.

Both of the barrow's two central burials feature skeletons of lone individuals lying on their left sides with their heads facing north.

One of the people was buried in a pit with gutters on each side and postholes at the corners, according to the Facebook post, which implies that they may have originally been placed inside a wooden structure within the barrow that has since rotted away. That person was buried with a pottery vessel that had presumably been offered as a grave good, and the second central burial also contained five worked pieces of flint, including an arrowhead and a sharp blade.

Prehistoric burials

The researchers are still analyzing the site. Traces of four later graves were discovered within the barrow itself, and the archaeologists hope to find out whether the people buried there were related to the high-status people in the central graves. 

"Similar burial mounds in Central Europe usually consist of only one, maximum two, burials," Krištuf said. "From this point of view, it will be interesting to see how the discovered graves are related to each other and whether they represent the burials of relatives." 

The archaeologists think the barrow was initially built at the site and that the other burials were made there over later generations.

"The first results show that the monumental burial mound stood here for many centuries and funeral and ritual activities of the local people took place in its vicinity," Krištuf said. "It was an important ritual place and landmark in the landscape at that time." 

Archaeological evidence shows that Neanderthals began marking caves as early as 75,000 years ago, but these markings were typically non-figurative. Until a few years ago, the oldest known figurative cave painting was a 21,000-year-old rock art panel in Lascaux, France, showing a bird-headed human charging a bison. But in 2019, archaeologists unearthed hundreds of examples of rock art in caves in the Maros-Pangkep karst. The rock art included a 15-foot-wide (4.5 meters) panel depicting human-like figures engaging with warty pigs (Sus celebensis) and anoas (Bubalus) — dwarf buffalos native to Sulawesi.

"Storytelling is a hugely important part of human evolution, and possibly even it helps to explain our success as a species. But finding evidence for it in art, especially very early cave art, is exceptionally rare," Adam Brumm, co-author of the new study and an archaeologist at Griffith University in Australia, said at a news conference. 

The archaeologists previously dated the panel rock art and found it to be at least 43,900 years old, while the oldest image they found in the area was of a 45,500-year-old warty pig. 

Now, using a more sensitive dating technique, the archaeologists found that the rock art is at least 4,000 years older than previously thought, making it around 48,000 years old. More strikingly, the archaeologists found a similar depiction of the human-like figure and warty pig at another cave in Leang Karampuang that was at least 51,200 years old, making it the oldest known narrative art. Their findings were published Wednesday (July 3) in the journal Nature. 

Related: Did art exist before modern humans? New discoveries raise big questions.

Archaeologists were intrigued by the narrative art's depiction of a part-human, part-animal figure, or therianthrope. 

"Archaeologists are very interested in depictions of therianthrope because it provides evidence for the ability to imagine the existence of a supernatural being, something that does not exist in real life," Brumm said. 

Previously, the earliest evidence of a therianthrope was the 40,000-year-old 'Lion Man' sculpture unearthed in a cave in Germany. 

"These depictions from Indonesia are pushing back the dates back nearly 20,000 years earlier, which is groundbreaking, really," said Derek Hodgson, an archaeologist and scientific advisor for INSCRIBE, a European-based project investigating the development of writing, who was not involved in the study.

The early evidence of a therianthrope is a sign of complex human cognition, Hodgson told Live Science. "You don't find any of these Neanderthals or early pre-human archaic species producing complex figurative art." 

To more accurately date the narrative art, the researchers used a technique called laser ablation uranium-series imaging. 

Previously, the scientists dated the cave paintings by carbon-dating small samples of cave "popcorn" — calcite clusters that have accumulated over thousands of years. 

But in the new study, Brumm and his team used even smaller calcite samples — just 0.002 inches (44 microns) long. By taking much smaller samples, the archaeologists gain a higher resolution of the age distribution of the calcite on the cave walls. The technique also minimizes the damage made to the artwork.

"It really changes the way we do the dating on record, and it can be applied to other records as well," study co-author Renaud Joannes-Boyau, a geochronologist at Southern Cross University in Australia, said at the news conference.  

But not everyone agrees. Paul Pettitt, a paleolithic archaeologist at Durham University in the U.K. who was not involved in the study, said that to suggest the art is a narrative, the researchers had to "really make a leap of faith." 

"The dating method is robust, but the team's interpretations are certainly not," he wrote in a statement emailed to Live Science. Looking at the images, it was unclear to him whether these paintings were isolated depictions that just happened to be next to each other. 

According to the authors, while the identity of the painters, most likely Homo sapiens, is a mystery, the lack of evidence for human occupations suggests that the cave might have been reserved for art-making. The cave is tucked away from the rest of the area at a higher elevation.

"It's possible that people, these early humans, were only going up into these high-level caves to make this art," study co-author Maxime Aubert, an archaeologist and geochemist at Griffith University, said at the news conference. "Perhaps there was stories and rituals associated with the viewing of the art, we don't know. But these seem to be special places in the landscape."

The team is planning to survey and date more rock art in the area. 

Recently, Adhi Agus Oktaviana, the study's lead author and archaeologist at the Center for Prehistory and Austronesian Studies (CPAS) in Indonesia, found a painting in another cave of three figures depicting a human, a half-human-half-bird and a bird figure. But the team has not analyzed the painting yet.

"It's very likely that there is some more beautiful ones hidden somewhere that we don't know," Aubert said.  

Editor's note: This article was updated at 1:38 p.m. EDT to include quotes from Paul Pettitt, a professor of Palaeolithic archaeology at Durham University in the U.K.

This discovery may help researchers better understand the festival known as Negro Election Day, when enslaved and free Black men voted for their own leader, who enforced laws and mediated disputes with the white community.

In the New England region, some of the people who were trafficked across the Atlantic Ocean in the early 1700s were of royal African heritage. They were brought to the area and forced to work at ports and on farms. In at least four colonies — Massachusetts, Connecticut, Rhode Island and New Hampshire — enslaved Africans maintained one of their customs: electing a leader known as a "king" or a "governor." 

One of these leaders, Pompey, may have been born a prince in West Africa and came to Massachusetts in bondage at some point in the early 1700s. Historical accounts suggest that Pompey was a community leader who hosted Negro Election Day events at his own property along the Saugus River just north of Boston, which he bought after being freed. 

"King Pompey was an esteemed leader in the Black community but his home and property have always been a mystery," Kabria Baumgartner, a historian at Northeastern University who is part of the research team looking for Pompey's house, said in a statement.

Related: Enslaved people were kidnapped from all across Africa, rare look at DNA from colonial cemetery reveals

The researchers first scoured historical property deeds to learn that Pompey purchased 2 acres (0.8 hectares) of land along the Saugus River in 1762, where he built a small stone house for himself and his wife, Phylis (or Phebe, it's unclear which is correct). The team then compared historical maps and newspaper articles with contemporary lidar-created maps — topography maps created from laser pulses shot from an aircraft — to narrow down the area of Pompey's house using specific landmarks. 

About 4 feet (1.2 meters) below ground, the team hit a foundation made of hand-chiseled river rocks, which matched descriptions in the historical records. "The big find was the handmade pebble foundation," Meghan Howey, an archaeologist at the University of New Hampshire who is part of the research team, said in the statement. "I'm extremely confident this is a foundation from the 1700s and everything that points to this being the home of King Pompey is very compelling." 

Researchers aren't sure exactly when Pompey was elected king, but historical records suggest he served in this position more than once in the 1750s, by which time he was hosting Negro Election Day at his own house.

Coinciding with the colonies-wide Election Day for white male property owners, in the mid-18th century Black people in New England gathered to select community leaders and to maintain ties with one another and with their African cultural heritage. The festival — which could last for up to a week — included music, dancing, singing and games. Participants wore fashionable clothing — often mimicking white people's dress — ate special food like gingerbread and held parades.

"I've always been fascinated by those fleeting private and intimate moments outside of the watchful eye of an enslaver when Black people could be themselves and enjoy each other and be in community," Baumgartner said. 

In 2022, the Massachusetts legislature established the third Saturday in July each year as Negro Election Day, continuing a tradition that began more than 280 years ago.

While archaeologists have found similar rock art designs elsewhere in South America, the newfound art "represents a new culture previously unknown," José Miguel Pérez-Gómez, an archaeologist and researcher at Simón Bolívar University in Caracas who is leading the team, told Live Science in an email.

Some of these designs, which researchers call "pictograms," were drawn in red and depict geometric motifs such as lines of dots, rows of X's, star-shaped patterns and straight lines that connect together to form a variety of designs. There are also simple depictions of leaves and stick figure drawings of people. Additionally, some of the images, called petroglyphs, were incised into the rock and also show a variety of geometric motifs. 

It's unclear why people created this art. "It is almost impossible to get into the minds of people living so many [thousands of] years ago" Pérez-Gómez said, but "definitely these signs had a ritual meaning." For instance, the different depictions may be related to birth, diseases, the renewal of nature or good hunting. The places where the rock art was created "most probably had a meaning and an importance within the landscape, just as the churches have a meaning for people today," Pérez-Gómez added. 

Related: Sprawling 8-mile-long 'canvas' of ice age beasts discovered hidden in Amazon rainforest

While it's unknown exactly how old the rock art is, similar rock art in Brazil has been dated to around 4,000 years ago. However Pérez-Gómez thinks that the examples in Venezuela may be older. 

Canaima National Park is a massive park, about the size of Belgium, that encompasses forests and mountainous terrain. One of its most famous features is Angel Falls, the tallest waterfall on land in the world. The park may have been the "ground zero" where this mysterious culture first developed, Pérez-Gómez said, before later dispersing to places as distant as the Amazon river, the Guianas and even southern Colombia, which have rock art similar to the newly found examples in Venezuela. 

The remains of ceramics and stone tools were also found at the 20 rock art sites and may have been used by the people who created the rock art, however more research needs to be done to say so for sure, Pérez-Gómez said. Additionally, more rock art sites are likely to be found in Canaima National Park as research continues, he noted. 

The research was presented at the "New Worlds New Ideas" prehistoric archaeological congress held in Valcamonica, Italy from June 26 to 29. A paper that discussed one of the rock art sites was published in November 2023 in the journal Rock Art Research.

But when did humans actually invent shoes? That's tricky to answer because the animal skins, plant fibers and other materials used to make shoes tend to break down over time. The oldest known shoes are more than 10,000 years old, but our ancestors may have worn them much earlier than that, fossilized footprints suggest.

The oldest shoes that researchers have directly dated are a pair of 10,400-year-old sandals recovered from Fort Rock Cave in central Oregon, according to Thomas Connolly, archaeological research director at the University of Oregon's Museum of Natural and Cultural History.

Archaeologists who began excavating at Fort Rock Cave in 1938 discovered dozens of sandals woven from sagebrush bark and other fibers. Similar footwear has been found at nearly a dozen sites in the northern and western Great Basin, the arid U.S. region between the Sierra Nevada and the Rocky Mountains, Connolly explained. "Generally, these are finely made, with a flat sole and foot cover," he told Live Science.

Related: 12 old shoes found in archaeological excavations from around the world

Scientists who interviewed Native groups in the Oregon area, such as the Klamath and Northern Paiute peoples, found that "in historic times, woven footwear was for winter use, especially for work around cold marshes and lakes where one might retrieve fishing or fowling nets, or harvest bulrushes for mats and baskets," Connolly said.

Although these sandals are porous, their fibers would have retained body heat to keep feet warm, even when they were soaked in water. "Ethnographer Samuel Barrett was told by his Klamath informants that woven shoes were worn so that 'one might in the dead of winter walk with comparative comfort through marshes where the water is extremely cold,'" Connolly said.

He noted that one set of human remains found in Nevada, known as the Spirit Cave Mummy, may have shoes that are older than the Fort Rock Cave sandals. The mummy, which is about 10,600 years old, has hide moccasins, Connolly said. However, scientists have not directly measured the age of the footwear.

150,000-year-old shoe prints?

While these examples are the oldest known footwear, there may be evidence that humans invented shoes much, much earlier. Fossil tracks on a beach in South Africa may be shoe prints dating back up to 150,000 years, according to a 2023 study. 

When Charles Helm, a research associate at Nelson Mandela University in South Africa, and his colleagues analyzed the fossil tracks, they noticed a resemblance to human footprints except for the absence of toe impressions, which suggested that whoever created the prints may have been wearing shoes. 

"There is something wonderfully evocative about thinking of our ancestors that long ago having the capacity to develop and wear shoes," Helm told Live Science. "Then, as now, protection from injury and from temperature extremes were probably an incentive to create footwear."

However, they found no direct fossil traces of any shoes. "It is probable that the organic substances from which ancient footwear was fashioned would long since have perished, and we therefore needed to look for other evidence," Helm said.

In the 2023 study, the researchers looked to the sandals used by the modern Indigenous San people on the sands of the Kalahari Desert for ideas as to what ancient footwear might have looked like. They also examined 2,000-year-old San rock art that depicted a shaman wearing shoes.

Helm and his colleagues crafted a variety of shoes, which they wore to create trackways on the sands of South Africa's south coast. They found that an open, hard-sole design with tracks made on moist, moderately soft sand best fit the fossil tracks.

"One hundred and fifty thousand years is pretty ancient, but I wouldn't dismiss it out of hand," Connolly said.

Editor's note: Updated at 3:40 p.m. EDT to note that the sandals in the image are not the 10,400-year-old shoes from Fort Rock Cave, but another ancient pair in the same style that were found in Oregon.

The artifacts, which were analyzed in a new study that used both scientific analyses and Aboriginal oral history, may have been used in a ritual spell carried out to bring harm to another person.

The artifacts are similar to a ritual practiced by the Gunaikurnai, an Indigenous group residing on Australia's southern coast, which involved smearing a wooden object with human or animal fat and then dropping it into a ritual fire. 

Given the parallels between the objects in the cave and the historically attested Gunaikurnai ritual, which was recorded by anthropologists in the late 19th century, Aboriginal elders sought out archaeological collaborators to excavate the cave, known as Cloggs Cave, and study the artifacts. Their results were published Monday (July 1) in the journal Nature Human Behaviour. 

Cloggs Cave was partly excavated in the early 1970s. In an email to Live Science, study first author Bruno David, an archaeologist at Monash University in Australia, said "the cave was never used as a general camping place, but rather only for special ritual purposes. It first began to be used this way around 25,000 years ago, and continued to be used this way until at least 1,600 years ago." 

A subsequent excavation undertaken in 2020 by David and his team revealed two sacred ritual installations, each comprising a small fireplace with a slightly burnt wooden stick coming out of it. Radiocarbon dating of the sticks showed that one was between 11,930 and 12,440 years old, while the other was between 10,870 and 11,210 years old, making them the oldest wooden artifacts ever found in Australia.

Related: Mysterious rock art painted by Aboriginal people depicts Indonesian warships, study suggests

The team found that both sticks had been deliberately altered, suggesting past people had trimmed, cut or scraped the sticks to make them very smooth. Further analysis showed that the sticks were both Casuarina, a native Australian pine tree, and that there were patches of an unknown residue on them. Chemical analysis of this residue using mass spectrometry — a technique that can identify individual molecules in a sample — revealed the presence of fatty acids, indicating that part of the stick had been smeared with animal or human fat of some sort.

Given the lack of food remains near the small fireplaces, the presence of a single smooth stick in each fireplace and the sticks' contact with fatty tissue, the researchers concluded that the 12,000-year-old installations they uncovered were used for a specific ritual purpose — one that appears to have been passed down over 500 generations from the end of the last ice age to very recent times.

"What these fire sticks tell us is that this is actually specifically about the culture of the Old Ancestors that continues to today," David said in a transcript of a conversation with Gunaikurnai Elder Russell Mullett. "Bringing in the community way — the cultural way — with some of the scientific techniques means that stories can be told." 

The study sets a high bar for investigating ancient ritual practice, Ben Marwick, an archaeologist at the University of Washington who was not involved in the study, told Live Science in an email. 

"There are older examples of more generic rituals, such as burial of the dead," Marwick said, "but this one is special because it is a specific ritual practice that has continued from time immemorial until recently."

While the archaeological work tying together 12,000-year-old ritual objects with 19th-century historical practices is a clear scientific triumph, it also points to a loss of Indigenous knowledge with the colonization and Westernization of Australia, according to Mullett.

Ethnographer Alfred Howitt recorded Gunaikurnai rituals in 1887, but "if he wasn't there, that knowledge may not well have been transferred on," Mullett said. "Because we're talking about times of mission stations, where the severing of cultural knowledge is occurring."

"The science can only tell you so much," David told Live Science in an email. "Incorporating traditional cultural knowledge provides an opportunity to tell a broader story about the Old Ancestors and the cultural landscape they lived in."

In the late 1960s, the splintered remains of a wooden bridge across the Thielle River were discovered along with iron and bronze weapons; pottery; and two dozen human and animal skeletons. Most of the recovered human skeletons were those of adult males, in some cases pinned underneath the beams of the bridge, which was initially constructed in 135 B.C. While a flood may have triggered the collapse, resulting in deaths, the other possible interpretation is a Celtic ritual offering of sacrificed humans and animals.

In a study published June 17 in the journal Scientific Reports, researchers used a variety of analysis techniques to suggest that there may have been a complicated sequence of events at the site, including both sacrifices and a bridge collapse. 

The researchers investigated the 20 human skeletons to determine each victim's age at death, sex and traumatic injuries. They discovered that most of the dead were male and that about half of the people had sustained blunt-force injuries around the time of death. However, most of the injuries were to the skull, which is at odds with the limb injuries expected in a collapse, and more closely match head trauma inflicted by others. Additional investigations of the animal remains revealed no evidence of sharp trauma that is usually seen in sacrificial contexts, supporting an accidental bridge collapse. 

Related: 2,300-year-old scissors and 'folded' sword discovered in a Celtic cremation tomb in Germany

The team also used carbon-14 analysis to date 11 of the human skeletons, with all of them falling between the third and first centuries B.C. Surprisingly, though, the oldest skeleton was dated to 361 to 152 B.C., while the most recent was dated to 167 B.C. to A.D. 7., suggesting that skeletons found in the river ended up there at slightly different times, some through the accident that destroyed the bridge and others through possible violent execution. 

In other words, some of the people who were pinned under the bridge may have been long dead when it collapsed.

To investigate the people further, the researchers employed isotope and DNA analyses on the 10 most well-preserved skeletons to see whether they were biologically related and whether they grew up somewhere other than Switzerland. Isotopes — variations of elements that have a different number of neutrons in their nuclei — become part of a person's teeth and bones through the water they drink and the food they eat, and can reveal where a person grew up. 

The analysis revealed that nine of them were biologically male and that there were no close genetic relationships. Further, the chemical analysis suggested that the people were descended from West or Central European peoples but that some of them moved around quite a bit during their lives.

Taken together, the evidence adds up to a violent and sudden accident taking place at the bridge, likely in the early first century B.C., "but this bridge had a prior life," study co-leader Marco Milella, a researcher in the Department Anthropology at the University of Bern in Switzerland, said in a statement. 

"It may have been a place of sacrifice, and it is conceivable that some corpses preceded the accident," Milella said. "There is no reason to choose between the two alternatives."