Archaeologists have unearthed the foundation of what appears to have been a massive, ancient structure, possibly a bridge leading to an artificial island, in what is now southeast Wales. The strange ruin, its discoverers say, is unlike anything found before in the United Kingdom and possibly all of Europe.

"It's a real mystery," said Steve Clarke, chairman and founding member of the Monmouth Archaeological Society, who discovered the structural remains earlier this month in Monmouth, Wales - a town known for its rich archaeological features. "Whatever it is, there's nothing else like it. It may well be unique."

Clarke and his team discovered the remnants of three giant timber beams placed alongside one another on a floodplainat the edge of an ancient lake that has long since filled with silt. After being set into the ground, the pieces of timber decayed, leaving anaerobic (oxygen-free) clay, which formed after silt filled in the timbers' empty slots, Clarke told LiveScience.

The team initially thought the timber structures were once sleeper beams, or shafts of timber placed in the ground to form the foundations of a house. However, the pieces appear to be too large for that purpose. While a typical sleeper beam would span about 1 foot (30 centimeters) across, these timber beams were over 3 feet wide and at least 50 feet long (or about 1 meter by 15 meters). The archaeologists are still digging and don't yet know how much longer the timbers are. Clarke says the structure's builders appear to have placed whole trees, cut in half lengthwise, into the ground.

British archaeologists have unearthed the remains of a mysterious prehistoric structure that might be older than Egypt's pyramids.

Discovered during work at a housing development in Monmouth, Wales, the bulky feature consists of a series of trenches possibly housing the timber foundations of a massive building.

"We have what appear to be huge parallel sleeper beams set close to the edge of an ancient, dried up lake," archaeologist Steve Clarke of Monmouth Archaeology told Discovery News.

Made from what seems to be entire tree trunks, the sleeper beams are huge, measuring more than 50 ft in lenght and more than 3 ft across.

"It's huge and presumably prehistoric but otherwise we haven't a clue what it is, we don't know how old it is and we don't know how long it is," Clarke said.

Continuing beyond the excavations, the timber structure was cut into the surface of a burnt mound, presumably dating to the Bronze Age.

The mysterious structure of Stonehenge may have been built as a symbol of peace and unity, according to a new theory by British researchers.

During the monument's construction around 3000 B.C. to 2500 B.C., Britain's Neolithic people were becoming increasingly unified, said study leader Mike Parker Pearson of the University of Sheffield.

"There was a growing islandwide culture - the same styles of houses, pottery and other material forms were used from Orkney to the south coast," Parker Pearson said in a statement, referring to the Orkney Islands of northern Scotland. "This was very different to the regionalism of previous centuries."

By definition, Stonehenge would have required cooperation, Parker Pearson added.

"Stonehenge itself was a massive undertaking, requiring the labor of thousands to move stones from as far away as west Wales, shaping them and erecting them. Just the work itself, requiring everything literally to pull together, would have been an act of unification," he said.

The new theory, detailed in a new book by Parker Pearson, Stonehenge: Exploring the Greatest Stone Age Mystery (Simon & Schuster, 2012), is one of many hypotheses about the mysterious monument. Theories range from completely far-fetched (space aliens or the wizard Merlin built it!) to far more evidence-based (the monument may have been an astronomical calendar, a burial site, or both).

The Queen of Sheba's genetic legacy may live on in Ethiopia, according to new research that finds evidence of long-ago genetic mixing between Ethiopian populations and Syrian and Israeli people.

The Queen of Sheba, known in Ethiopia as Makeda, is mentioned in both the Bible and the Quran. The Bible discusses diplomatic relations between this monarch and King Solomon of Israel, but Ethiopian tradition holds that their relationship went deeper: Makeda's son, Menelik I, the first emperor of Ethiopia, is said to be Solomon's offspring.

Whether this tale is true or not, new evidence reveals close links between Ethiopia and groups outside of Africa. Some Ethiopians have 40-50 percent of their genomes that match more closely with populations outside of Africa than those within, while the rest of the genomes more closely match African populations, said study researcher Toomas Kivisild of the University of Cambridge.

"We calculated genetic distances and found that these non-African regions of the genome are closest to the populations in Egypt, Israel and Syria," Kivislid said in a statement.

A mass grave of prehistoric "giant wombats" - a marsupial the size of a rhinoceros - has been discovered in Australia, according to reports.

The discovery of about 50 diprotodon skeletons was the biggest to date and could shed light on why the animal become extinct, BBC News reported.

Diprotodon, a relative of the modern wombat, was the largest marsupial that ever lived and had a pouch that was large enough to carry an adult human.

According to the Australian Museum, it was "widespread across Australia when the first indigenous people arrived, co-existing with them for thousands of years before becoming extinct about 25,000 years ago." Fortunately for the people, diprotodon ate plants.

"Exact reasons for the extinction of Diprotodon remain unclear. It seems to have co-existed with Aboriginal people for over 20,000 years, so the 'blitzkrieg' model (extinction upon the arrival of humans) does not hold for Diprotodon," according to a post on the Museum's website.

Were the giant statues on Easter Island actually "walked" to their final resting spots?

Researchers have unveiled a new theory that may redefine the historical understanding of how natives on Easter Island transported the iconic moai statues.

Writing in July's issue of National Geographic magazine, California State University at Long Beach archeologist Carl Lipo and Hawaii anthropologist Terry Hunt postulate that Polynesian natives used a system of ropes and manpower to walk the statues across the island.

"A lot of what people think they know about the island turns out to be not true," Lipo says.

Using the ropes, islanders would stand on each side of the statues, swaying them back and forth to create the walking effect.

Popular theory has held that the islanders created sled-like devices out of the island's trees to cart the statues. That theory also claims that deforestation from the island's inhabitants as part of the statue transporting process was directly tied to the population's eventual downfall.

The sandy dunes of the Sahara may seem an unlikely place for a dairy farm, but about 7,000 years ago, herders tended and milked cattle in what is now desolate desert, new research shows.

About 10,000 years ago, the Sahara desert went through a phase called the Holocene African Humid Period.

Fossilized bones show that by the sixth millennium B.C. (or about 7,000 years ago), cattle, sheep and goats roamed over green savanna, and rock art depicts cows with full udders. The occasional image even shows milking, said study researcher Julie Dunne, a doctoral student at the University of Bristol. But it's difficult to get a firm date for those images.

By analyzing pottery fragments, Dunne and her colleagues have now shown that these early herders were not only milking their livestock, but also processing that milk into products like yogurt, cheese and butter.

"The most exciting thing about this is that milk is one of the only foodstuffs that gives us carbohydrates, protein and fat," all in one substance, Dunne told LiveScience. "So it was incredibly beneficial for prehistoric people to use milk."

Saharan dairies

Dunne and her colleagues analyzed tiny fragments of pottery taken from the Takarkori rock shelter, a prehistoric dwelling in the Libyan Sahara. They ground up small pieces of the pottery, conducting chemical analyses to investigate the proteins and fats embedded in the shards. By doing so, the researchers could see what the pots once held.

They found evidence of a varied diet, with signs found for plant oils and animal fat. The most common fats were of animal origin, Dunne said, with some deriving from flesh and others from milk. The most dairy-fat rich pottery shards came from the same time periods when more cattle bones are found in the cave layers, the researchers reported today (June 20) in the journal Nature.

By looking at variations in the carbon molecules in these preserved fats, the researchers were able to get an idea of what kind of plants the cattle were eating. They found their diets varied between so-called C3, or woody plants, and C4 plants, which include grasses grains and dry-weather plants. (C3 and C4 refer to the type of photosynthesis these plants use.)

That fits with the archaeological understanding of this early herding civilization as moving between seasonal camps, Dunne said.

"It suggests that they were moving between summer and winter camps and eating different plants at one place than another, so this all ties together very nicely," she said.

Welsh people could lay claim to be the most ancient Britons, according to scientists who have drawn up a genetic map of the British Isles.

Research suggests the Welsh are genetically distinct from the rest of mainland Britain.

Professor Peter Donnelly, of Oxford University, said the Welsh carry DNA which could be traced back to the last Ice Age, 10,000 years ago.

The project surveyed 2,000 people in rural areas across Britain.

Participants, as well as their parents and grandparents, had to be born in those areas to be included in the study.

Prof Donnelly, a professor of statistical science at Oxford University and director of the Wellcome Trust centre for human genetics, said DNA samples were analysed at about 500,000 different points.

After comparing statistics, a map was compiled which showed Wales and Cornwall stood out.

Prof Donnelly said: "People from Wales are genetically relatively distinct, they look different genetically from much of the rest of mainland Britain, and actually people in north Wales look relatively distinct from people in south Wales."

While there were traces of migrant groups across the UK, there were fewer in Wales and Cornwall.

He said people from south and north Wales genetically have "fairly large similarities with the ancestry of people from Ireland on the one hand and France on the other, which we think is most likely to be a combination of remnants of very ancient populations who moved across into Britain after the last Ice Age.

"And potentially also, people travelling up the Atlantic coast of France and Spain and settling in Wales many thousands of years ago".

The world's first collective graveyard of a herd of mammoths has been discovered at the excavation site for coal in Serbia.

Heavy torrential rain earlier this week exposed the remains of what could be up to six mammoths, at an open pit mine in Kostolac, east of Belgrade not far from a site where two other mammoth remains had been uncovered in recent years.

Miomir Korac, director of the Archeological Project Viminacium, which is named after the Roman provincial capital along the Danube River, said that the discovery came as a complete surprise.

The archeologists were first alerted to one set of giant remains of a mammoth that was damaged by the mining machinery. But then the heavy downpour rinsed away the yellow sand.