There are just five preserved skins of Jerdon’s courser that survive and two of them are in the ornithological collection at the Natural History Museum, Tring. A colleague Stuart Piertney took scrapings from the membrane lining the inside the mystery egg and shavings from a toe-pad from one of the two courser skins. “The sequences obtained from the egg and the toe-pad were identical, indicating that they had come from the same species”
You can only imagine what kind of story involves a tiny egg from an already presumably extinct species from India surviving the trip to Aberdeen in 1917. If you have never visited Tring Museum - you should.