RE: Disney's Dinosaur Trailer

["Norton, Patrick" <Patrick.Norton@state.me.us>]

JimC wrote, in part:

> the pterosaur's
> inner arm muscles will be more massive than the bird's,
> because they powered
>  their
> flight stroke a bit differently.

As a bit of an aside, I've often wondered why birds have retained more   
muscle mass in their wings (think of a tasty fried chicken wing) than   
pterosaurs or bats, which have very little muscle mass within the wing   
itself.  The wings of pterosaurs and bats were (are) mostly membrane and   
bony struts controlled by tendons. My guess would be that, per unit area   
of wing surface, lifting the wing of a bird requires more energy than   
lifting a pterosaur or bat wing.

Pat