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

RE: Do we have dromaeosaurid evolution backward?




(plain text; sorry)


> Date: Thu, 25 Aug 2011 05:47:24 +0000
> From: keenir@hotmail.com
> Subject: RE: Do we have dromaeosaurid evolution backward?
> 
> 
> 
> 
> 
> > Date: Thu, 25 Aug 2011 15:28:23 +1000
> > From: tijawi@gmail.com
> > To: dinosaur@usc.edu
> > Subject: Re: Do we have dromaeosaurid evolution backward?
> > 
> > David Marjanovic <david.marjanovic@gmx.at> wrote:
> > >> As I see it, one major problem with this idea is that if large,
> > >> pennaceous feathers originally evolved for aerodynamic purposes,
> > >> these feathers are unlikely to have arisen in "large" (2-4m long)
> > >> theropods that used their forelimbs for catching prey.
> > >
> > > I suppose that's where Hopp & Orsen (1998) come in.
> > 
> > 
> > Using the forelimbs to help incubate eggs might explain the presence
> > of big pennaceous feathers. But it doesn't explain why those feathers
> > would be aerodynamic. 
> 
> Maybe they wouldn't be aerodynamic initially...but eventually.
> 
> its like with possums and squirrels: they may not all have gliding abilities, 
> but most of them have figured out that if they jump off a branch, they can 
> escape danger.
>