A PARTIALLY COMPOSITE ELEPHANT BIRD EGG

The Elephant Bird was thought to be the giant flying beast known as the Roc (or Ruhk) in the tales of Sinbad and accounts of Marco Polo's voyages. The bird grew to around 10 or 11 feet in height and whilst probably unable to devour an elephant, as the Roc was reputed to do, it certainly was the largest bird ever to have lived. It was estimated to weigh up to 1100lbs (the largest ostriches might grow to 8 feet in height and weigh 300lbs).
The birds are thought to have gone extinct between the 14th and 17th centuries.