In 2010, bioarchaeologist Matthew Collins of the University of Copenhagen and his colleagues realized that the parchment used in medieval manuscripts, which is made of scraped and stretched animal skins, was actually a repository of information about the history of domestic animals in Europe.

Chris Baraniuk at New Scientist reports that Collins and his team have since begun collecting the dry eraser waste of skins left when conservators gently cleaned the manuscripts. Using these scraps, they’ve been able to draw out the DNA and proteins of the animal that sourced the parchment as well as that of any bookworms and humans that had come in contact with the page since.

At a recent symposium on bioarchaeology at Oxford’s Bodleian Library, the researchers presented an unpublished paper where they applied DNA techniques as well as traditional techniques to the 1,000-year-old York Gospels, an Anglo-Saxon manuscript, which is one of the few manuscripts to survive the Norman Conquest and the Protestant Reformation.

Ann Gibbons at Science reports that analysis of the parchment led to several surprises. For instance, the 167 folio pages of the York Gospels were made mainly from female calves, which is unusual since it’s believed they would normally be allowed to grow up and reproduce. But documents report that a cattle disease struck the region around the time the manuscript was produced, meaning there may have been many stillborn or sick calves around to provide the material.

Gibbons also reports that 20 percent of the DNA extracted from the York Gospels was human— most of it from the bacteria that lived on the skin and noses of priests who took an oath by kissing certain pages. That and other bacteria could give some insight into the health of people in Middle Ages York.

A similar analysis of a Gospel of Luke manuscript by Collins and his colleagues revealed the book was made from the skins of eight-and-a-half calves, ten-and-a-half sheep, and half a goat, as well as a cover from roe deer and a strap from fallow or red deer. Such mixed parchment suggests that scribes had to carefully manage their resources since their favored skin was not always available.

There are so many possibilities raised by the developing techniques that Gibbons reports researchers don’t even know what questions to ask. Bookworm DNA could help determine what region a book was produced or traveled to; parchment DNA could help trace the changes in livestock types and breeds over time; it’s even possible to find the DNA of specific historical individuals who handled a book during their lifetime.

While scholars have long mined medieval manuscripts to learn about the development of language and writing styles from the texts and glean information about daily life from the illustrations (and paw prints), this new lens into the manuscripts offers a whole new way to mine information from manuscripts and bring lost chapters of history to life.