A team of archaeologists from the University of Florida have discovered in St. Augustine the ruins of a church more than 300 years old that belonged to a mission of the Spanish colonial period.

The archaeologists believe it could be the oldest stone building of Spain's colonial period and one of the largest mission churches built during that time in Florida.

Researchers from the Florida Museum of Natural History, located on the UF campus in Gainesville, discovered coquina stones and foundations indicating a structure some 27 meters (90 feet) long by 12 meters (40 feet) high, which would be "the only mission church made of stone," the university said in a communique.

The ruins were found at the place where the first Franciscan mission was built in Florida, called Nombre de Dios (Name of God), which remained active from 1587 until 1760.

It was a monumental project with modest beginnings: a small group of scholars and some index cards. The plan was to explore a long-dead language that would reveal an ancient world of chariots and concubines, royal decrees and diaries - and omens that came from the heavens and sheep livers.

The year: 1921. The place: The University of Chicago. The project: Assembling an Assyrian dictionary based on words recorded on clay or stone tablets unearthed from ruins in Iraq, Iran, Syria and Turkey, written in a language that hadn't been uttered for more than 2,000 years. The scholars knew the project would take a long time. No one quite expected how very long.

Decades passed. The team grew. Scholars arrived from Vienna, Paris, Copenhagen, Jerusalem, Berlin, Helsinki, Baghdad and London, joining others from the U.S. and Canada. One generation gave way to the next, one century faded into the next. Some signed on early in their careers; they were still toiling away at retirement. The work was slow, sometimes frustrating and decidedly low-tech: Typewriters. Mimeograph machines. And index cards. Eventually, nearly 2 million of them.

And now, 90 years later, a finale. The Chicago Assyrian Dictionary is now officially complete - 21 volumes of Akkadian, a Semitic language (with several dialects, including Assyrian) that endured for 2,500 years. The project is more encyclopedia than glossary, offering a window into the ancient society of Mesopotamia, now modern-day Iraq, through every conceivable form of writing: love letters, recipes, tax records, medical prescriptions, astronomical observations, religious texts, contracts, epics, poems and more.

Why is there a need for a dictionary of a language last written around A.D. 100 that only a small number of scholars worldwide know of? Gil Stein, director of the university's Oriental Institute (the dictionary's home), has a ready answer:

"The Assyrian Dictionary gives us the key into the world's first urban civilization," he says. "Virtually everything that we take for granted ... has its origins in Mesopotamia, whether it's the origins of cities, of state societies, the invention of the wheel, the way we measure time, and most important the invention of writing.

"If we ever want to understand our roots," Stein adds, "we have to understand this first great civilization."

Changing climate observed in the Rocky Mountains

Scientists who study prehistoric remains know they have a huge find at Snowmass, probably the biggest of their careers.

Digging furiously for 18 days last fall as winter closed in, they uncovered the remains of eight to 10 American mastodons, four Columbian mammoths and a Jefferson's ground sloth, the first ever found in Colorado and the highest elevation sample anywhere in North America.

Although a herbivore, the ground sloth was the size of a grizzly bear and "capable of ripping your face off if you got too close to it," said Kirk Johnson, chief curator at the Denver Museum of Nature and Science, at a recent press conference.

That's conjectural, as ground sloths and most other species found at the Snowmass site disappeared 10,000 years ago, soon after the last great ice sheets retreated. Other species remain, such as the camel, whose tooth was found at Snowmass. But scientists aren't sure whether the genus of the extinct Camelops, had a hump, as camels today do, or lacked one, like their modern relative the llama.

On the beaches of southern California you can sometimes find clumps of a sticky black substance with a texture halfway between molasses and rubber. Could these tar balls - collected by humans for thousands of years - provide evidence that our long-standing relationship with hydrocarbons was toxic from the outset?

Long before we started asphalting roads, prehistoric people around the world used bitumen, which seeps from the ground naturally in places. Archaeological finds suggest that California's prehistoric locals, the Chumash people, eagerly collected the tar balls. They used them to caulk the seams of ocean-going craft and waterproof woven baskets to make drinking vessels, as well as for making casts for broken bones and poultices for sore joints. Some Chumash even chewed bitumen like gum.

We now know that bitumen can be a source of polycyclic aromatic hydrocarbons (PAHs) - pollutants that have been linked to a number of health problems (see "Poisonous ingredients"). To find out whether California's tar balls had the potential to damage the Chumash's health, Sebastian Wärmländer of Stockholm University in Sweden and colleagues analysed samples taken from Californian beaches and from the La Brea tar pits in Los Angeles. They found the tar contained 44 PAHs, including many known carcinogens.

An ancient Roman shipwreck nearly 2,000 years old may once have held an aquarium onboard capable of carrying live fish, archaeologists suggest.

The shipwreck, which lay 6 miles (nearly 10 kilometers) off the town of Grado in Italy, was discovered by accident in 1986. Approximately 55 feet (16.5 meters) long, it dated back to the mid-second century and had a cargo of about 600 large vases known as amphoras that contained sardines, salted mackerel and other fish products.

Curiously, its hull possessed a unique feature -- near its keel was a lead pipe at least 2.7 inches (7 cm) wide and 51 inches (1.3 meters) long. Why pierce its bottom with a hole that seawater could rise up?

Scientists now suggest this pipe was connected to a hand-operated pump to suck up water. The aim? To keep a constant supply of flowing, oxygenated water into a fish tank onboard the ship.

A Wiltshire mound where the legendary wizard Merlin was purported to be buried has been found to date back to 2400 BC.

Radiocarbon dating tests were carried out on charcoal samples taken from Marlborough Mound, which lies in Marlborough College's grounds.

The 19m (62ft) high mound had previously mystified historians. Some believed it dated back to about 600 AD.

English Heritage said: "This is a very exciting time for British prehistory."

Dig leader Jim Leary said: "This is an astonishing discovery.

"The Marlborough Mound has been one of the biggest mysteries in the Wessex landscape.

"For centuries people have wondered whether it is Silbury's little sister; and now we have an answer. "

'Dramatic history'

Silbury Hill, an artificial man-made mound about five miles away, also dates back to 2,400 BC.

Marlborough Mound was reused as a castle and became an important fortress for the Norman and Plantagenet kings.

Incan fortresses built some 500 years ago have been discovered along an extinct volcano in northern Ecuador, revealing evidence of a war fought by the Inca just before the Spanish conquistadors arrived in the Andes.

"We're seeing evidence for a pre-Columbian frontier, or borderline, that we think existed between Inca fortresses and Ecuadorian people's fortresses," project director Samuel Connell, of Foothill College in California, told LiveScience.

The team has identified what they think are 20 fortresses built by the Inca and two forts that were built by a people from Ecuador known as the Cayambe. The volcano is called Pambamarca.

The team's research was presented in March at the 76th annual meeting of the Society for American Archaeology (SAA), in Sacramento, Calif.

"We know that there are many, many fortresses throughout northern Ecuador that haven't been identified one way or the other," said Chad Gifford, of Columbia University, who is also a project director.

Easter Island is branded into popular consciousness as the home of the mysterious and towering moai statues, but these are not the only curiosity the South Pacific island holds. Where the moai are fascinating for their unknown purpose and mysterious craftsmen, the island's lost language of Rongorongo is equally perplexing. The unique written language seems to have appeared suddenly in the 1700s, but within just two centuries it was exiled to obscurity.

Known as Rapa Nui to the island's inhabitants, Rongorongo is a writing system comprised of pictographs. It has been found carved into many oblong wooden tablets and other artifacts from the island's history. The art of writing was not known in any nearby islands and the script's mere existence is sufficient to confound anthropologists. The most plausible explanation so far has been that the Easter Islanders were inspired by the writing they observed in 1770 when the Spanish claimed the island. However, despite its recency, no linguist or archaeologist has been able to successfully decipher the Rongorongo language.

Dig reveals thousands of stone items at portage on South Nation River

An Ottawa archeologist has discovered a rare site of human activity in Eastern Ontario from between 3,500 and 9,000 years ago. Paul Thibaudeau, an adjunct professor at Carleton University, has been leading a team of archeologists, students, and volunteers collecting artifacts from a dig near Casselman, east of Ottawa. It is only one of a half-dozen sites in Eastern Ontario that are considered reliable evidence of human presence during the period.

Thousands of stone items have been found at what Thibaudeau said was a portage around a waterfall and rapids on the South Nation River. The spot is believed to have been a temporary hunting and animal-skinning camp. Small stone tools used in skinning, remnants of tools, and waste from the toolmaking process have been found. "They were coming, staying briefly, and moving on, that's what we can tell right now," he said.

He knew he was onto something when one of his crew, Kelly Berckmans, of Ottawa and a Carleton student, found what appeared to be a piece of glass but turned out to be a crystal quartz "end scraper."

"When I saw that -that got me excited. When I started seeing a lot of quartz flakes, a lot of chipped stone in the other test pits I said something is going on here."

The end of the Norse settlements on Greenland likely will remain shrouded in mystery. While there is scant written evidence of the colony's demise in the 14th and early 15th centuries, archaeological remains can fill some of the blanks, but not all.

What climate scientists have been able to ascertain is that an extended cold snap, called the Little Ice Age, gripped Greenland beginning in the 1400s. This has been cited as a major cause of the Norse's disappearance. Now researchers led by Brown University show the climate turned colder in an earlier span of several decades, setting in motion the end of the Greenland Norse. Their findings appear in Proceedings of the National Academy of Sciences.

The Brown scientists' finding comes from the first reconstruction of 5,600 years of climate history from two lakes in Kangerlussuaq, near the Norse "Western Settlement." Unlike ice cores taken from the Greenland ice sheet hundreds of miles inland, the new lake core measurements reflect air temperatures where the Vikings lived, as well as those experienced by the Saqqaq and the Dorset, Stone Age cultures that preceded them.

"This is the first quantitative temperature record from the area they were living in," said William D'Andrea, the paper's first author, who earned his doctorate in geological sciences at Brown and is now a postdoctoral researcher at the University of Massachusetts - Amherst. "So we can say there is a definite cooling trend in the region right before the Norse disappear."