The 13in tall specimen was laid by a Great Elephant Bird in Madagascar almost 400 years ago and is now a rare antique. It is bigger than a rugby ball and measures more than 3ft round its circumference. The flightless Great Elephant Birds, which were 10ft and weighed a half a tonne, were wiped out by hunters in the mid-1600s. Their eggs – around 300 times the size of a hen's egg – are the biggest of any creature including dinosaurs. Duncan Phillips, organiser of the Chelsea Antiques Fair, where the egg is on show, said: "This is the largest known egg in the world. "Elephant Bird eggs are extremely rare and this is the biggest one we have ever seen. "They are very highly prized by collectors and interior designers and there might not be another one on the market for 50 years. "It's a real talking point in a room because you can ask people to guess where it comes from." The few Elephant Birds eggs that survive were collected by Victorian explorers who pieced together shell fragments found in old nests on the Indian Ocean islands to reconstruct whole eggs. source---------http://www.telegraph.co.uk