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Re: Again: origin of bird flight



----- Original Message -----
From: "Ronald Orenstein" <ornstn@home.com>
To: <david.marjanovic@gmx.at>; "The Dinosaur Mailing List"
<dinosaur@usc.edu>
Sent: Sunday, March 18, 2001 8:27 AM
Subject: Re: Again: origin of bird flight


> At 06:37 PM 17/03/01 +0100, David Marjanovic wrote:
> >True, but I disagree with the "Pouncing Proavis" hypothesis:
> >1. It's mantra time: There Were No Trees At Solnhofen. (I don't think 3 m
> >high bushes are suitable for such pouncing.)
>
> Further mantra: so what?  Just because Archaeopteryx happened to live in
> the Solnhofen ecosystem does not mean that (a) it evolved there, (b)
flight
> evolved in that type of ecosystem or (c) Archaeopteryx really is the First
> Bird so anything about how it lived apples directly to how flight
> evolved.  There are plenty of closely-related living birds today that
> occupy quite different habitats (not to mention other groups of animals -
> if baboons were the only fossil primates would we be forced to conclude
> that primates did not evolve in trees?).  Archie just happened to be the
> one that fossilized - it could have had very close relatives in tall
forest
> elsewhere.

OK, er... still I think *Archaeopteryx* doesn't look anywhere near a
climber, so close relatives probably didn't climb much either.

Nesting in trees, BTW, which has often been cited as an advantage of
arboreality, seems to be a rather recent innovation among Neornithes;
*Gobipteryx* nests are AFAIK also known to lie on the ground.

> >Or for steering underwater... just like pelicans do today with their
stiff
> >tail feathers. (c) Ebel 1996
>
> I'm afraid I can see not the slightest resemblance between Archaeopteryx
> and any swimming bird.  The limb and body proportions are about as wrong
as
> they can be - I would be utterly astonished if it could, or did, swim
> underwater.
>
> >Fits underwater flight, too.
>
> Underwater flyers today are highly specialized in ways Archaeopteryx
simply
> is not.  For one thing, birds that do this today (alcids, penguins,
> scoters) have long bodies and short limbs - quite unlike Archaeopteryx.

There are unspecialized underwater fliers today -- dippers. I won't say that
*Archaeopteryx* didn't run around on land if necessary.

There must be a reason why 1 *Compsognathus* specimen is known from the
Solnhofen/Eichstätt area, while 8* specimens of *Archaeopteryx* plus the
isolated feather are known from there... Ebel suggests the later were more
likely to die in/above the place where they fossilized.

*the 8th specimen is undescribed and unprepared, and AFAIK nobody knows at
the moment who found it when where... it's rather disarticulated, judging
from the mediocre little photo I've seen in _kosmos_.