Re: Birdosaurs

[tuckr@digital.net]

The following may be of interest
 (http://www.sciencedaily.com/story.asp?filename=980324074921):


> Source: American Museum Of Natural History 
>  Posted 3/24/98 
>  
> 
> Researchers Announce Discovery Of Skulls Of Bizarre Animals Showing Advanced 
> Stage In Transition Between Dinosaurs And Birds 
> 
> March 19, 1998--A team of researchers from the American Museum of Natural 
> History and George Washington University announced today in the journal 
> Nature the discovery of the first known skulls of a bizarre group of ancient 
> animals called the Alvarezsauridae. This group (which includes the creatu
> re called Mononykus), is of special interest because it provides further 
> evidence in support of the theory that birds evolved from dinosaurs and 
> reveals an advanced stage in this transition. Numerous physical 
> characteristics in the fossil skulls show that these strange creatures were 
> actually ea
> rly birds, challenging the traditional view that all primitive birds looked 
> similar to their modern-day cousins. 
> 
> The new fossils, which date from the late Cretaceous Period and are 
> approximately 70 million years old, were found in the Gobi Desert of 
> Mongolia. They were discovered during one of a series of joint American 
> Museum of Natural History/Mongolian Academy of Sciences expeditions to search 
> for dinos
> aurs and other fossils. 
> 
> The research team named their find Shuvuuia deserti, from the Mongolian word 
> shuvuu, meaning "bird," and the Latin for desert, in reference to the ancient 
> climate in which the animals lived. Shuvuuia deserti, which was about the 
> size of a turkey, walked on two legs, had a long tail and neck, and
>  quite unlike most primitive birds, had stubby forearms that ended in a 
> single, blunt claw. How the animals used these strange appendages is a 
> mystery, but they were clearly unable to fly. 
> 
> While creatures similar to Shuvuuia deserti, including the early bird 
> Mononykus, have been found in Mongolia, Argentina, and North America, none of 
> the specimens was found with a skull. Fossil skulls are extremely important 
> because they contain key physical characteristics that enable researcher
> s to trace the evolutionary history of different lifeforms. 
> 
> The Shuvuuia deserti skulls reveal an important physical characteristic that 
> is found only in birds: the animal was capable of "prokinesis," the movement 
> of the snout up and down independently of the rest of the skull. This allowed 
> the animal to open its mouth quite wide in order to eat large fo
> od items. The diet of Shuvuuia deserti is not known, but may have included 
> insects, as well as lizards and even small mammals. Prokinesis is considered 
> a very advanced characteristic of birds - to find evidence of this 
> characteristic in such a primitive bird is surprising and indicates that this
>  ability actually arose early in bird evolution. 
> 
> A detailed analysis of its anatomical features shows that Shuvuuia deserti 
> and all other Alavarezsauridea are the most primitive known fossil birds with 
> the exception of the famous Archaeopteryx, discovered in 1861. Ironically, 
> while Archaeopteryx is more primitive, it fits the stereotypical con
> ception of a bird much better than the more advanced Shuvuuia deserti. The 
> new discovery illustrates the complexity of the evolution of birds and hints 
> at the number of surprises yet to be uncovered in tracing the development of 
> their lineage. 
> 
> The authors of the Nature paper are: Luis M. Chiappe, Chapman Fellow and 
> research associate in the Museum's Department of Ornithology; Mark A. Norell, 
> chairman and curator in the Museum's Department of Vertebrate Paleontology; 
> and James M. Clark, the Ronald Weintraub Assistant Professor of Biolo
> gy, Department of Biological Sciences, George Washington University. 
> 
> In addition to support from the American Museum of Natural History, the Gobi 
> Expedition is supported by Mercedes-Benz, which is the principal sponsor of 
> the Museum's 1997, 1998, and 1999 expeditions to Mongolia, providing both 
> financial support and vehicles for use by the expedition team. The Go
> bi project is also supported by the National Science Foundation and the Jaffe 
> Foundation. 

See also (for starters):

Chatterjee, S., 1997, _The Rise of Birds: 225 Million Years of Evolution_, 
Johns Hopkins University Press. xvi + 312 pp.

Currie, P. J., and Padian, K. (eds.), 1997, _Encyclopedia of Dinosaurs_, 
Academic Press. xxx + 869 pp.

Farlow, J. O., and Brett-Surman, M. K. (eds.), 1997, _The Complete Dinosaur_, 
Indiana University Press. xiv + 752 pp.

And don't forget Dinogeorge's views!

-= Tuck =-