It was known elephant birds were ratites-an ancient group of mostly big, flightless birds, including emus and cassowaries from Australia, ostriches from Africa, rheas from South America and others.
众所周知,象鸟属于平胸类鸟群,一种古老的无飞行能力的大型鸟,这类鸟包括澳大利亚的鸸鹋、鹤鸵,非洲的鸵鸟,南美的美洲鸵等。