(Cue Woman screaming in the background. Thank you)
http://www.timesofmalta.com/articles/view/20100602/world/australian-rock-art-find-could-be-40-000-years-old.310182
In this case, I wanted to draw attention to the fact that Australian rock-art does indeed depict the giant birds facetiously called Demon Ducks of Doom, including depictions of their distinctive type of head. The news item supposes the artwork is therefore very old: but on the contrary the big birds could have survived the mass extinction and the paintings could be more recent.
The Demon Ducks (which are of course not related to ducks in the least but are more closely related to the cranes, rails and bustards; it is perhaps better to call them Bigger Bustards) incidentally would have stood between eight and nine feet tall in life, with the females presumably larger than the males.
Best Wishes, Dale D.
I thought that Genyornis (Dormornithidae)was the most likely candidate for the rock painting, which being an Anseriform, is closely related to the ducks and geese. If not Genyornis, it is still certainly a member of the Dormornithidae.
ReplyDeleteThanks, Max. The Dromornithids (your spelling is incorrect) are definitely related to waterfowl, but IMHO placing them in Anseriformes is probably being overly literal about an ambiguous relationship. The problem I have with attributing the genus in this case is the absolute size of the currently-reportedly-living species: it is up there with the maximum Dromornithids. The head of the larger bird in the painting is more like Bullockornis, which is why its picture is up there and why the headline. At the same time you will see that I have listed this entry on my index as under Genyornis. I was not being insistant that the genus must be Bullockornis, only that my impression was that that genus was a better match.
ReplyDeleteIf you think that my interpretation of the taxonomy is too loose, I would be only too glad to change it, since the taxonomy of birds is one thing that is always being updated these days. At my last information, My understanding was that the matter was unsettled. Since it is not an area where I claim expertise, I freely admit I might have been inaccurate.
Best Wishes, Dale D.
Sorry Dale, I didn't mean to imply that you were being insistent about it being Bullockornis, I just wanted to suggest that it was Genyornis because this was (as far as I am aware) the only species still to be alive, though soon to go extinct, when the painting was made. Genyornis has a fairly robust skull, larger in proportion to the bird than that in the smaller specimen in the painting, but perhaps not as massive as the larger individual. However, I can't find any studies on Genyornis skull growth changes, so I have no idea if it could be as massive as the specimen in the painting. I think with so little to go on, it could be either species, though as Bullockornis is around 15 million years old, and Genyornis 45,000 years old, I would still propose Genyornis as the species in question. However, that picture you used is a really nice one, and it certainly adds to the piece!
ReplyDeleteAs I understand it, Anseriform taxonomy is very much in flux. As they were one of the first major groups of birds to evolve, there are many lineages represented by one or two species. Where they all fit into the 'family tree' is currently unknown, and where Dromornithids come into it is unknown, but as far as I know, they are most likely within Anseriformes, but were an early branch off the group. I would give you a paper reference, but I can't access any which tackle this issue.
Your quite right, I have no idea why I spelt it incorrectly twice. Its been a long couple of days filled with lab work....
If the rock art is accurate about the larger bird and just plain lazy about the smaller one, we could be talking about a new species of Genornis that has re-evolved some of Bullockornis' features: that's my guess anyway. And it seems to be unusually sexually dimorphic.
ReplyDeleteThe thing about the Anseriformes IS that they are so highly derived: that is the problem. A different highly-derived branch might not be close enough to be considered in the same group: you have that problem with lumpers and splitters again. I have read the original releases for the group and I think the question is still unresolved until we get some general ground rules of Taxonomy more firmly set. I know I'm always saying that, but it never pays to measure everything with a rubber ruler.
Best Wishes, Dale D.