‘Big Bird’ ancestor discovered
AN ANCIENT BIRD species distantly related to the duck has been discovered using 26-million-year-old bones found in north-west Queensland.
Examining skull bones, a sternum and leg and foot bones from the Riversleigh World Heritage Fossil Site, a team of scientists from Flinders University in South Australia and the University of New South Wales concluded that the bird was the first member of the lineage of Dromornis species, the ancient ‘Mihirung’ family of giant birds.
Professor Suzanne Hand from UNSW, who found the fossils with her colleague Mike Archer, said “the very large and distinctive bones of this new ‘Big Bird’ are quite common in the Riversleigh fossil deposits, and are easily spotted by scientists and visitors to the site.”
A flightless, plant-eating bird, D. murrayi weighed 250kg and lived in the late Oligocene to the early Miocene, about 33 to 20 million years ago. By eight million years ago, D. murrayi had evolved into D. stirtoni, which was the largest bird the world has ever known, averaging about 450kg but weighing up to a whopping 650kg – about as much as a large horse.
“Mihirungs were giant flightless birds only found in Australia and are known only from fossils,” said Dr Trevor Worthy from Flinders University, lead author of the paper, which was published in the Journal of Vertebrate Paleontology. “The largest stood two metres high at its back and reached well over three metres at the head,” he said.
Seven species of Mihirung birds are generally recognised, with the last five named in 1979 by Professor Patricia Vickers-Rich of Monash University in Melbourne.
This new species brings that number to eight, with D. murrayi named after Peter Murray, former Northern Territory Museum curator and co-author of the book Magnificent Mihirungs.
According to Tony the last species of the Mihirung family probably died out about 50,000 years ago.