Common ostrich other members of Palaeognathae and thus the flighted tinamous are the sister group to the extinct moa. It is distinctive in its appearance, with a long neck and legs, and can run for a long time at a speed of or even up to about , the fastest land speed of any bird. The common ostrich is the largest living species of bird and lays the largest eggs of any living bird (extinct elephant birds of Madagascar and the giant moa of New Zealand laid larger eggs). The common ostrich's diet consists mainly of plant matter, though it also eats
Elephant bird documentary "Attenborough and the Giant Egg", presented by Attenborough, about his personal scientific quest to discover the secrets of the elephant bird and its egg. A complete eggshell is also available in the collection of the University of Wrocław Museum of Natural History. There is also an intact specimen of an elephant bird's egg (contrasted with the eggs from other bird species, including a hummingbird's) on display at the Delaware Museum of Natural History, just outside Wilmington, Delaware, US, and another in the Natural History Museum, London. The Melbourne Museum has two "Aepyornis" eggs. The first was acquired for £100