RE: Gallimimid & Ornithomimid arms -- shrinkable?

["Thomas R. Holtz, Jr." <tholtz@geol.umd.edu>]

> From: owner-dinosaur@usc.edu [mailto:owner-dinosaur@usc.edu]On Behalf Of
> Rodlox
>
>  Wondering here...
>
>  What did the "Ostrich mimic" dinosaurs use their arms for?  (if I recall
> 'predatory dinosaurs of the world', they may've used their arms for grasping
> branches to facilitate feeding....yes?).

I'd go with that.

>  Could those arms shrink to Tyrannosaurid proportions?

Sure, if natural selection (or some other mode of evolution) favored that. As 
far as we know it didn't. (Although some workers have
suggested that alvarezsaurids were close relatives of ornithomimosaurs. If you 
modified their hypothesis and made alvarezsaurids a
clade within Ornithomimidae, then you would have an example of this...)


                Thomas R. Holtz, Jr.
                Vertebrate Paleontologist
Department of Geology           Director, Earth, Life & Time Program
University of Maryland          College Park Scholars
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