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Re: Disney's Dinosaur Trailer

Patrick Norton wrote:

> JimC wrote:
> >Pat, why do you say ...... snipped
> Wing muscles, according to those researchers (and
> discussed by Pat Shipman in her book "Taking wing") are muscles that
> originate from and attach to bones of the wing itself and excludes muscles
> that orginate on the carina or furcula.

We are using the same definition for 'wing muscles', with the possible
difference that I am also excluding the muscles that attach from the shoulder to
the wing.  We all agree that they were massive and therefore aren't our subject.

>   Wing muscles in birds are not used
> for flapping or for flexion or extension of the wing during flapping flight,

In Quetzalcoatlus they are used for that purpose,  to assist flapping and for
flexion and extension during flapping flight.  I suspect that they served a
similar function in at least some other pterosaurs.

> but to act upon the feathers, radius, ulna and the carpometacarpus to adjust
> the wing airfoil shape to enhance manueverability.

They had the same function in Quetz (with one obvious exception), but some of
them were also used to power part of the flapping cycle, and the launch (when
acting as a front leg, rather than as a wing).

> Bats have much less massive wing muscles (relatively) than birds, and I
> admit to assuming that pterosaurs did as well.  If pterosaurs had massive
> wing muscles (again, not "flight" muscles) I'd be interested in knowing what
> they were used for.

Supplementing the power of the pectorals and other 'flight muscles' for one
thing.  I believe (please correct me if I'm wrong) that you are assuming that
pterosaur wingbeat kinematics are essentially identical with bird wingbeat
kinematics, and are powered identically.  They aren't, though there are many
functional similarities.  In Quetzalcoatlus, some of the 'wing muscles' should
be considered as 'flight muscles' as well because they are providing power for
the wing beat, particularly at slower speeds.

> > We are talking about the inner wing here, inboard of the wrist<
> I was talking about wing muscles.

By your definition, these are wing muscles.  I'm excluding the muscles of the
shoulder from our discussion.

> >not the outer wing which was mostly (but not entirely) tendon and
> membrane.<
> My point precisely.

Not exactly.  Your definition of 'wing muscles' comprises all those which do not
attach from the torso to the wing.  There are a lot of  'em between the shoulder
and the wrist.  They're massive, and I think you may be ignoring them.