“Goose like”

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.

Other dromornithids like Dromornis itself also have a very distinct beak shape. I find comparisions between the dromornithid taxa and potential dietary habits need to be made before jumping to conclusions.