An egg of one of the world's most endangered species of bird, dating back almost 100 years, has been discovered at a university.
Details of the surprise find in a collection at the University of Aberdeen's zoology museum in 2008 have just been revealed.
The egg is 2-3cm long and is similar to the size of a small duck's egg, but it took five years to establish the egg's identity, including DNA analysis.
Breeding habits of the south Indian bird called Jerdon's Courser, or Rhinoptilus bitorquatus, are unknown and an egg has never been found by an ornithologist.
Experts hope that the discovery will help conservationists identify the species' egg in their work to save it from extinction.
Dr Alan Knox, the university's emeritus head of museums, said: "I was looking through drawers of uncatalogued eggs in the university's zoology museum when I spotted an egg labelled as belonging to this species.
"It was one of those eureka moments - finding something nobody else knows about, something so rare and exciting. I could hardly believe my eyes.
"My first question was how do you identify something that the books say has never been discovered?