It was an amazing find as it was, a cache of 1,700-year-old speckled chicken eggs discovered during an excavation in a Roman well Buckinghamshire.
But to the surprise of archaeologists and naturalists, a scan revealed that one of the eggs recovered intact still contained fluid – thought to be a mixture of yolk and egg white – inside, possibly giving away secrets about the bird that laid it almost two. millennia ago.
The “Aylesbury egg” is one of four found in 2010 alongside a woven basket, pottery, leather shoes and animal bone as a site was surveyed ahead of a major development.
Despite the experts extracting them as carefully as possible, three broke and produced an unforgettable sulphurous smell, but one was completely preserved.
Edward Biddulph, the senior project manager at Oxford Archaeology, who oversaw the excavation, said it was surprising to find what is believed to be the only intact egg from the period in Britain. “We often find pieces of shells, but not intact eggs,” he said.
Discussions were held last year about how and when to display the egg Dana Goodburn-Brown, an archaeological conservator and materials expert, suggested they scan it to help decide how best to preserve it.
Biddulph said: “The egg was even more amazing. It still contained its liquid, the yolk and the white.” It looks like the yolk and egg white have mixed together.
“We might have expected it to have leached out over the centuries, but it’s still there. This is absolutely incredible. It may be the oldest egg of its kind in the world.”
Biddulph said the egg was deliberately placed in a pit that was used as a pit for malting and brewing. “It was a wet area next to a Roman road. It is possible that the eggs were placed there as a votive offering. The basket we found may have contained bread.”
The egg was taken to the Natural History Museum in London. Biddulph said it felt a little scary to ride the tube and walk around the capital with such an extraordinary and fragile egg in his care.
Douglas Russell, the senior curator of the museum’s collection of bird eggs and nests, was consulted on how to preserve the egg and remove the contents without breaking it.
There are older eggs with contents, such as mummified eggs, but Russell said this is believed to be the oldest egg accidentally preserved. A small hole can be made in the egg to extract the contents and try to find out more about the bird that laid it.
Goodburn-Brown said: “The egg is one of the coolest and most challenging archaeological finds to investigate and preserve. Being the temporary caretaker and investigator of this Roman egg counts as one of the great highlights of my 40-year career.”