Re: Pterosaurs, and more pterosaurs!

["Chris Bennett" <cbennett@bridgeport.edu>]

----- Original Message -----
From: "Nick Pharris" <npharris@umich.edu>
To: "Dinosaur Listserver" <dinosaur@usc.edu>
Sent: Friday, February 06, 2004 12:41 PM
Subject: Re: Pterosaurs, and more pterosaurs!


> Quoting Chris Bennett <cbennett@bridgeport.edu>:
>
> > I could produce a data matrix and analyze with PAUP to produce
> > a "cladogram" showing that Gnathosaurus, gharials, and needlefish were
most
> > closely related if I used enough characters related to adaptations to
> > feeding on fishes, but that would not prove a close relationship.
>
> This brings to mind something that's been bothering me for a while about
> *Gnathosaurus*.  I'm going from memory here, but I seem to remember that
in the
> skull reconstructions in Wellnhofer's encyclopedia, the back part of the
> *Gnathosaurus* skull looks more like *Germanodactylus* than it looks like
> *Ctenochasma*, while the back part of *Ctenochasma*'s skull looks more
like an
> ornithocheirid.  Are these just faulty reconstructions, or is it possible
that
> *G* and *C* are not closely related after all and merely share similar
feeding
> adaptations?

I take it you are refering to the line drawings of skull reconstructions in
left lateral view.  Most of them go back to Wellnhofer's 1970 monograph on
the Solnhofen pterodactyloids.  I disagree with his reconstruction of the
back of the skull of a number of Solnhofen pterodactyloids including
Gnathosaurus, but you need to understand that that reconstruction is based
on a single specimen that is crushed dorsoventrally.  Reconstructions in
lateral view based on dorsoventrally crushed specimens may not be reliable,
and so one should not put too much weight on differences between the
reconstructions of Gnathosaurus and Ctenochasma.

Chris


S. Christopher Bennett, Ph.D.
Assistant Professor of Basic Sciences
College of Chiropractic
University of Bridgeport
Bridgeport, CT  06601
http://www.bridgeport.edu/~cbennett

"Savor the sun--but when the clouds come make animals"  (Hexum)