On a desert ridge in Arizona’s Verde Valley sits Tuzigoot National Monument, the ruins of a 110-room pueblo built about 1,000 years ago by a pre-Columbian culture archaeologists call the Sinagua. Tuzigoot was originally excavated in the 1930s with funding from the New Deal Works Progress Administration. It was also then that one of the first excavators, who was Apache, gave the site its name, which means “crooked water” in the Apache language. The history of the Sinagua people is shrouded in mystery, as they had abandoned Tuzigoot and other settlements in the area by the time the Spanish arrived. They are known for the remains of their pit houses and pueblos that dot central Arizona, as well as clay pottery called Alameda Brown Ware, and expansive, intricate petroglyphs that seem to whirl across rock faces. While the exact reason for the Sinagua’s departure from the Verde Valley remains unknown, Native American oral histories provide clues that supplement archaeological data. “Tuzigoot and other Sinagua settlements appear in the oral history,” explains Matt Guebard, chief of resources management and archaeologist at Tuzigoot. “Our interpretation of the site is absolutely informed by collaboration with native communities.”

The Site

The ruin, which is currently a property of the National Park Service, ranges between two and three stories tall, and is looped by a circular path from which visitors can see into the pueblo and back down across the valley and the Tavasci Marsh. The first room visitors encounter, known as the plaza, is the only flat space on the hill and would have been used as a communal area. At the top of the pueblo, the Park Service has fully reconstructed a tower room to give visitors an impression of what the village looked like in its prime, when residents lived in close, apartment-like quarters.

While You’re There

Before climbing up to the pueblo, begin your tour at the visitor center, a building dating to the original 1935 excavations and designed to blend in with the ruins. Tuzigoot’s museum provides a historical overview of the Sinagua culture and displays artifacts uncovered from the site. In a day, an ambitious traveler can also take in nearby Montezuma Castle National Monument, another Sinagua pueblo ruin built into a sheer limestone cliff. The semi-abandoned copper mining town of Jerome, a popular tourist destination, is nearby, and Sedona is just over 20 miles away.

Archaeologists have unearthed a fragment of an ivory icon at the Byzantine frontier fortress of Rusokastro in southeastern Bulgaria. Depicting the archangel Gabriel and Saint Basil, the 3.2-inch-tall icon dates to the tenth century and was likely made in Constantinople on the orders of an emperor, says archaeologist Milen Nikolov of the Burgas Regional Historical Museum. “This was an expensive—very expensive—item,” says Nikolov, who is surprised that such an elaborate artifact made its way to the imperial frontier. He and his team discovered the object, which was once a wing of a triptych, beneath a large thirteenth-century building that was probably the residence of the local governor.

Around A.D. 990, the monks at Saint Augustine’s monastery in Canterbury, England, made an illuminated copy of the four gospels of the New Testament. This parchment manuscript is one of the oldest books in Europe and is still used in ceremonies at the Cathedral and Metropolitan Church of Saint Peter in York, better known as York Minster, where it has been kept since about A.D. 1020. All of that history has left its traces on the book’s pages. Now, researchers have found a way to use erasers to recover DNA from the book’s parchment pages without harming them. DNA sampling typically requires destroying a small piece of whatever is being studied. “There was no way they were going to let us cut the York Gospel,” says Sarah Fiddyment of the University of York, “so being able to do it noninvasively is incredible because we get access to these books that otherwise we’d never get to see.”

The technique that Fiddyment has helped pioneer requires only a white plastic eraser of the kind typically used in drawing classes. She rubs the eraser on the parchment page, creating a triboelectric effect—essentially static electricity—which allows tiny amounts of the parchment and whatever else might be on the page to stick to the bits that come off of the eraser. The eraser waste is then collected and treated with chemicals to recover proteins and DNA. The technique can be used on any protein-based material such as bone or ivory, according to Fiddyment.

The research team’s analysis has been able to show that the book is primarily made of calfskin and that four of the five calves whose gender could be identified were female—not male as might be expected for people who raised cattle for dairying. This finding has led the researchers to speculate that the parchment may have come from cattle that died during an outbreak of a disease called murrain that swept through cattle herds in Great Britain and Ireland during the late 900s.

One document that was added to the book in the fourteenth century was made of sheepskin. It records property that was owned by the church in York. In some cases sheepskin was preferred for legal documents because it is not as durable as calfskin. It will come apart if you try to erase what’s written on it, and therefore it is easier to detect whether the writing has been altered.

Human DNA recovered from the book also revealed which pages had been handled most frequently. Aside from a page that had been restored in the mid-twentieth century, which had an anomalously large amount of DNA, those that show the most use were in folio 6, a bundle of calfskin parchment that makes up pages 23–30 in the book. Those pages contain the oaths that the clergy use to swear themselves to the church. “Every canon of York has sworn their oath on this book since the thirteenth century,” says Victoria Harrison, assistant director of collections and learning at York Minster.

The study also revealed a hidden danger to the future preservation of the York Gospel. The DNA of bacteria from the genus Saccharopolyspora, which can cause a measles-like spotting of the pages, was found throughout the book. Conservators will now have a chance to stop the bacteria before it can damage the manuscript.

This work opens up a new area of DNA research—examining parchment documents to study changes in livestock over hundreds of years. “Parchment is this incredible untapped resource,” says Fiddyment. “Basically what you’ve got all over the world is millions of animals that are dated and located.”