[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: emu history




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

_________________________________________________________________
Rethink your business approach for the new year with the helpful tips here. http://special.msn.com/bcentral/prep04.armx