BBC NEWS | UK | England | Nottinghamshire | Eggs-perts rule on chicken riddle
“I would argue it is a chicken egg if it has a chicken in it,” said Prof Papineau.

“If a kangaroo laid an egg from which an ostrich hatched, that would surely be an ostrich egg, not a kangaroo egg,” he added.

Charles Bournes, chairman of trade body Great British Chicken, said “Eggs were around long before the first chicken arrived.

“Of course they may not have been chicken eggs as we see them today but they were eggs,” he said.