Species: B. planei
Bullockornis was a rather large, and now extinct, flightless bird that lived approximately 15 million years ago in the Middle Miocene in Australia.
Bullockornis stood approximately 2.5 meters (8 feet) tall, and weighed approximately 250 kg (550 lb.). It was a cross between an emu and a tank. It had a round body, vestigial wings, powerful clawed legs, and a massive beak the size of your head, well-suited to shearing. It is currently assumed that the large beak and strong beak muscles were used for killing and eating meat; they were most likely omnivorous, eating both plants and a good range of marsupials, such as giant wombats, miscellaneous kangaroos, and possums.
Unfortunately, Bullockornis has gained the colourful nickname "Demon Duck of Doom", despite looking very little like a duck. The beak is closer to a finch, and they had strong running legs. However, we do suspect that the Bullockornis' closest living relative are the waterfowl (the Anseriformes), which include the ducks and geese. Bullockornis was not the largest of the Dromornithidae; that would have been the Dromornis stirtoni, another "duck" that measured in at 3 meters tall and weighed about 500 kilos. The infamous giant moa was even taller, at 3.6 meters, but most of that was neck; the moa weighed about 230 kg.
Bullockornis translates to 'ox-bird', in a bastard mix of Old English and Greek.
Magnificent Mihirungs: The Colossal Flightless Birds of the Australian Dreamtime By Peter F. Murray, Patricia Vickers-Rich
The Theatrical Tanystropheus blog (with picture of the skull)
Tera, The Encyclopedia of New Zealand (with artists rendering).
Wikipedia page (with skull AND popular statues in Kings Park, Western Australia)