The ostrich (Struthio camelus) is a large flightless bird native to Africa. The common ostrich shares the order Struthioniformes with the kiwis, emus, rheas, and cassowaries. It is distinctive in its appearance, with a long neck and legs, and can run at up to about 70 km/h (43 mph), 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. It lives in nomadic groups of 5 to 50 birds.