#dromornithidae

little cenozoic guys

So a new study has examined the first complete Genyornis skull. It is truly a mastery of phylogenetics, firmly placing Dromornithidae as indeed true waterfowl.

However one of the conclusions of the study is a bit sus. It claims that Genyornis, and by proxy other dromornithids, fed primarily on aquatic plants. This is based on two main factors: small gastroliths indicating softer plant diet and a beak superficially similar to that of a goose. Geese, however, are notoriously the most terrestrial of living waterfowl, having a diet dominated by grass and only a small percentage of aquatic plants. Some like the Cape Barren Goose (Cereopsis novaehollandiae) and the Nene (Branta sandvicensis) even have reduced webbing on the feet.

Dromornithids are known to have nail-like claws, a point even pointed out in the new paper. This is consistent with a more terrestrial ecology for these birds. I find it more plausible that they were feeding on soft foliage rather than quatic plants, which is still concurrent with the study's conclusion of their demise as Australia became more arid, since fewer soft leaved trees remained.

Researcher discovers ancestor of biggest bird ever

A newly discovered distant relative of the duck has just been hailed as an ancestor of the biggest bird the world has ever known by a group of Australian palaeontologists.

They say Dromornis murrayi, which at 250kg was originally the 'baby' of the ancient 'Mihirung' family of Dromornis giant birds, eventually evolved into the world's biggest bird, D. stirtoni, before going extinct.

"It lived in the late Oligocene – early Miocene, and was the first member of the lineage of Dromornis species," says Dr Trevor Worthy, from Flinders University in South Australia, who led the study.

"Originally, it was the smallest, at a pretty hefty 250 kg, but by eight million years ago it had evolved into D. stirtoni, which averaged a whopping 450 kg – with some individuals reaching 650 kg – the largest birds the world has known."

Dr Worthy's team of palaeontologists, from Finders University and University of New South Wales, revealed the news in a study just published in the Journal of Vertebrate Paleontology.

"Mihirungs were giant flightless birds only found in Australia and are known only from fossils," said Dr Worthy. "The largest stood two metres high at its back and reached well over three metres at the head.

"They survived until the Pleistocene period when Genyornis newtoni, the last species, died out, probably about 50,000 years ago."

Seven species in four genera of the bird are generally recognised, with the last five named in 1979 by Patricia Vickers Rich, now a Professor at Monash University.