A volunteer found the egg and its significance was seen later
An egg thought to be the last specimen from Charles Darwin's HMS Beagle voyage has been rediscovered at Cambridge University's Zoology Museum.
Records show Darwin himself caused the damage when he packed the egg in a box that was too small.
The chocolate brown egg, one of 16 collected on the naturalist's trip, was catalogued by volunteer Liz Wetton.
At first she did not recognise the egg as a new discovery but when her manager reviewed her work saw its significance.
Ms Wetton said the specimen just had C. Darwin written on it but when collections manager Matthew Lowe was reviewing her work he discovered no one knew about the existence of this specimen.
"There are so many historical treasures in the collection, Liz did not realise this was a new discovery," he said.
"To have rediscovered a Beagle specimen in the 200th year of Darwin's birth is special enough, but to have evidence that Darwin himself broke it is a wonderful twist."
Mr Lowe and curator of ornithology Dr Mike Brooke, traced the specimen's origin in the notebook of Professor Alfred Newton, a friend of Darwin's and Professor of Zoology in the latter 19th Century.
Newton had written: "One egg, received through Frank Darwin, having been sent to me by his father who said he got it at Maldonado (Uruguay) and that it belonged to the Common Tinamou of those parts.
"The great man put it into too small a box and hence its unhappy state."