RE: Phil Currie celebration, tyrant skin, and other things

["Tim Williams" <twilliams_alpha@hotmail.com>]

Tracy Ford wrote:

>    Something that needs to be considered is grooming. If they have
> feathers they also have to be able to groom and clean them. Tyrannosaurs
> couldn't reach around and clean itself.


Here's the way I see it.  The feathers of tyrannosaurs (if they had them)
would probably be very simple structures, more like hair or down than the
flight feathers of modern birds.  I'm not saying that only flying birds take
assidious care of their plumage.  But if the feathers of tyrannosaurs were
simple filamentous structures, and present only on certain parts of the body
(say, on the postorbital, or nape of the neck), then they may not have
needed grooming.  A roll in the mud or stream may have sufficed.

The bristles of elephants and hippopotamids come to mind when I think of
feathers and tyrannosaurids.  The ancestors of elephants and hippos were at
one stage quite small and fuzzy (if you go back far enough).  Their present
near-nakedness is undoubtedly secondary and size-related.

Pure speculation, of course.  But I would guess that tyrannosaurs did at
least have a few feathers; and the absence of feathers from most of its hide
was a derived character.


Tim


------------------------------------------------------------

Timothy J. Williams

USDA/ARS Researcher
Agronomy Hall
Iowa State University
Ames IA 50014

Phone: 515 294 9233
Fax:   515 294 3163

_____________________
_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com