Re: Again: origin of bird flight

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

David Marjanovic wrote:

> Your argument about size is true, and I can
> imagine that a dromaeosaur could lurk clinging to a tree trunk in the
> position Chatterjee has suggested (though climbing in this position must
> have been very difficult, and the poor dromaeosaur would have had to jump
> off backwards at its prey, respectively to turn around in the air

No, it only climbed trunks to get into the branches - once there, the little 
predator had a wonderful vantage point.  Or, as Naish (2001) has suggested, 
certain small theropods could clamber up trees using branches as hand- (and 
foot-) holds.

> The "pouncing on prey" hypothesis by Garner, Taylor & Thomas has one 
> logical
> problem for me -- it seems to require quite large animals that pounced down
> from _high_ ambushes on rather large prey that couldn't escape while the
> predator was jumping down.

Why?

> I can't imagine *Caudipteryx* or smaller ones
> hunting insects that way!

What about frogs, urodeles, lizards, small mammals, eggs, baby dinosaurs...

(Though Taylor, in the following article which is
> all what I have on this hypothesis, makes a reasonably good case IMHO for
> *Caudipteryx* being an insect-eater, like the aardwolf, which also has
> gastroliths.)

Makes absolute sense to me.


> I really wait for troodontids, alvarezsaurs and yandangornithids from
> Liáoníng...

Or a tyrannosaurid (either a small species or a juvenile - either would 
probably be feathered.)


Tim

>


------------------------------------------------------------

Timothy J. Williams

USDA/ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014

Phone: 515 294 9233
Fax:   515 294 3163

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