Re: emu history

["Tim Williams" <twilliams_alpha@hotmail.com>]

I haven't been paying as much attention to this emu thread as I would have 
liked, so apologies if this has been mentioned already:

There is a fossil Australian ratite that is thought to be close to the 
divergence between emus (_Dromaius_) and cassowaries (_Casuarius_), and 
appropriately named _Emuarius_.

Boles, W.E. (1992). Revision of _Dromaius gidju_ Patterson and Rich 1987 
from Riversleigh, northwestern Queensland, Australia, with a reassessment of 
its generic position.  Natural History Museum Los Angeles County, Science 
Series 36: 195-208.

Also, aside from the Casuariformes, there is another group of extinct 
large-sized flightless birds from Australia, the dromornithids (mihirungs).  
These guys could be HUGE - the heaviest known birds, AFAIK, even outsizing 
the elephant bird.  The dromornithids were once dumped in the Casuariformes, 
but it is now widely recognized that they are no more closely related to 
casuariforms than to any other ratite group.  Further, there is good 
evidence that dromornithids are not even be ratites, but closer to the 
anseriforms than to paleognaths (ratites+tinamous), and so may be close to 
the base of the anseriforms.  If (as some studies suggest) paleognaths and 
galloanserine birds are consecutive basal outgroups in the Neornithes, then 
there may not be a great deal of light between paleognaths and basal 
anseriforms.

If dromornithids are some sort of galloanserine bird, then they are not the 
only group of large-bodied, flightless, cursorial birds that have been moved 
out of the ratites.  The genus _Eremopezus_ (long extinct), from continental 
Africa, which was once regarded as an aepyornithid, appears to be a 
neognath, perhaps a gruiform.  Its toes may have been prehensile.  
Gastornithids and phorurhacids also got pretty big, but they have never been 
considered ratites, AFAIK.

Rasmussen, D. T., Simons, E. L., Hertel, F. and Judd, A. (2001).  Hindlimb 
of a giant terrestrial bird from the upper Eocene, Fayum, Egypt. 
Palaeontology 42: 325-337.



Tim

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