[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Giant birds (again)




> Due to technical difficulties (Norm, your system claimed not to know
> you, so listproc unsubscribed you) the enclosed message didn't get
> distributed.  Since this gives me an opportunity to say something
> first, I recommend that people interested in this subject search the
> archives for messages by Alan Brush describing some of his data
> indicating that feathers did not derive from scales.
>
> -- MPR
>
> ----------------- start of forwarded message
> From: "King, Norm R" <NKing@usi.edu>
> To: "'dinosaur@usc.edu'" <dinosaur@usc.edu>
> Subject: Re:  Giant birds (again)
> Date: Fri, 19 Nov 1999 13:11:20 -0600
>
> I know this thread seems to have died, but I've been busy, and just got
> around to reading this.
>
> tkeese wrote (11/9/99, 2:25p):
>
> >> . . . calling ankylosuar "birds" is pretty bad, too.<
>
> To which dinogeorge responded (11/9/99, 3:06p):
>
> > Not really, especially when it gets you to thinking that ankylosaur
> > scutes and spines might be modified forms of feathers (or rather,
> > that feathers might be modified forms of scutes).  It just seems
> > peculiar at first.
>
>
> I've been mulling over that thought, and some of its implications, since
it
> was posted.  I still find it peculiar.
>
> I think it's easier to suppose that these are independent structures
derived
> from the same pre-existing feature.  And I even wonder about that.  Are
> scutes and feathers really homologous?  I thought ankylosaur scutes are
> composed of dermal bone rather than keratin.  I also thought that most
> people think feathers are related in some way to scales, although the
> details may be unclear.  I had not heard the same thing about ankylosaur
> scutes (but maybe I've missed something).  Surely the osteoderms of all
> thyreophorans have a common origin.  So, then, the back plates of
> Stegosaurus, with their high degree of vascularization and (blood?)
sinuses,
> would also be just modifed feathers.  (NOT!)   Are ankylosaur scutes
> vascular?
In addition to these points (could've sworn I already sent this message - oh
well), the material identified as Dynamosaurus imperiosus which was later