Archaeologists Were ‘Amazed’ to Find That a 1,700-Year-Old Chicken Egg Still Has Liquid Inside

New research shows that an intact chicken egg laid in Roman Britain 1,700 years ago still contains liquid inside, making it the only known egg of its kind in the world.

“This is the oldest unintentionally preserved avian egg I have ever seen,” says Douglas G.D. Russell, senior curator of birds’ eggs and nests at London’s Natural History Museum (NHM), in a statement to CNN’s Issy Ronald. “That makes it fascinating.”

The egg was one of four unearthed in a waterlogged Roman pit in Aylesbury, England, during a 2010 excavation. They rested alongside a woven basket, pottery vessels, leather shoes and animal bone. Three of the fragile eggs were initially uncracked, but two broke as they were removed from the site, releasing an “unforgettable sulfurous smell,” reports the Guardian’s Steven Morris.

Just one egg survived—and years after the discovery, archaeologists have cracked even more of its mysteries.

A team at the University of Kent conducted a micro-CT scan of the egg, which yields 3D images, over the summer. The images revealed that it retains its liquid interior, a two millennia-old mixture of its yolk and albumen. Researchers were “amazed” to learn that the egg was even rarer than previously thought, according to a statement from Buckinghamshire Council.

“We might have expected it to have leached out over the centuries, but it is still there,” says Edward Biddulph, senior project manager at Oxford Archaeology, which oversaw the excavation, to the Guardian. “It is absolutely incredible.”

Older eggs that still retain their contents do exist, such as a collection of mummified eggs held by the museum that were likely excavated in Egypt in 1898. Still, Russell says no other naturally preserved eggs as old as this one are known, per CNN.

“Going forward, it will be very exciting to see if we can use any of the modern imaging and analysis techniques here at the NHM to shed further light on exactly which species laid the egg and its potential archaeological significance,” adds Russell.

Experts think the eggs were placed next to the pit as a votive offering. The pit was used as a well for malting and brewing beer until the end of the third century, when passersby began contributing small objects as sacrifices.

The egg is now being kept in the Discover Bucks Museum in Aylesbury as conservators develop a plan to extract its contents without compromising its shell. According to CNN, Biddulph says that researchers plan to make a small hole in the shell after creating a 3D model.

“It’s a bit like blowing an egg—but obviously a much finer process,” says Biddulph, per BBC News’ Helen Burchell.

Analysis of the preserved contents could reveal even more details about the discovery’s origins.

“There is huge potential for scientific research,” adds Biddulph. “This is the next stage in the life of this remarkable egg.”

Catherine Duncan | READ MORE

Catherine Duncan is an intern with Smithsonian magazine.