Re: [dinosaur] Archaeopteryx had active flapping flight ability based on wing bone geometry (free pdf)

[Tim Williams <tijawi@gmail.com>]

Ruben Safir <ruben@mrbrklyn.com> wrote:

> And yet there Archaeopteryx is, a bird which obviously will need to run
> to get enough lift to fly.  It can't really be denied.


And yet, it has been denied.  Read the literature - including the work
cited here.  You'll find that a lot of your assertions (and
assumptions) have been directly refuted.


> If Swans need a
> running start, Archaeopteryx, which is better designed for running, and
> less designed for a leap and winged launch, would need it even more so.


Swans need a running start because of their aquatic adaptations, as
Mike stated (more than once).  Hindlimb morphology is the major
determinant for a running versus stationary take-off.

As for _Archaeopteryx_, the evidence suggests that it was capable of a
flight stroke (see the Voeten &c study).  It could also leap - as
David says, it was lighter than a swan and had proportionally much
longer legs.  The ability to leap would be unremarkable for a small
cursorial theropod like _Archaeopteryx_.

Put those together (leap + flight stroke), and you get an aerial
launch. I really don't see the BFD.


> That is today.  Our bird has been extinct for quite a while.  There is no 
> reason to derive Archaeopteryx's take off from modern birds.


Irrespective of whether you invoke a running take-off or a stationary
take-off, _Archaeopteryx_'s take-off is still based on modern birds.
The vast majority of birds employ a stationary take-off (as do bats
and flying insects).  Certain kinds of birds are exceptional in using
a running take-off (like swans). The question is, for _Archaeopteryx_,
which scenario is best supported by the science?  And by science I
mean actual aerodynamic and biophysical modelling, not intuition and
'just-so' stories.  _Archaeopteryx_ may be 150 million years old, but
the same laws of physics apply.


>In fact, it is likely impossible.


Sorry, but the scientific data say otherwise.