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
Largest prehistoric animals size. Total length was probably up to in female and they weighed about . The largest extinct "Titanohierax" was a giant hawk about 8 kilograms that lived in the Antilles, where it was among the top predators. The largest-known in this group was a giant flightless "Sylviornis", a bird long and weighing up to about . The largest-known songbird is the extinct giant grosbeak ("Chloridops regiskongi") at long. The largest-known cormorant was the spectacled cormorant of the North Pacific ("Phalacrocorax perspicillatus"), which became extinct around 1850, was larger still, averaging around and . The largest-known in this group—which has been