Flightless bird also included here. Flightless bird Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species including the well known ratites (ostrich, emu, cassowary, rhea and kiwi) and penguins. The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird, is the ostrich (2.7 m, 156 kg). Ostriches are farmed for their decorative feathers, meat and their skins, which are used to make leather. Many domesticated birds, such as the domestic chicken and domestic
Largest prehistoric animals along with the closely related "Eotriceratops xerinsularis" both with estimated lengths of . Ojoceratops and several other ceratopsians rival them in size. The very largest-known ornithopods, like "Shantungosaurus" were as heavy as medium-sized sauropods at up to , and in length. The largest-known birds of all time might have been the elephant birds of Madagascar. Of almost the same size was the Australian "Dromornis stirtoni". Both were about tall. The elephant birds were up to and "Dromornis stirtoni" was up to in weight. The tallest bird ever was the giant moa ("Dinornis maximus") at tall. The largest-known flight-capable bird was