Re: Tar and feathers

[Mike Taylor <mike@indexdata.com>]

> Date: Wed, 09 Apr 2003 12:17:23 -0500
> From: "Tim Williams" <twilliams_alpha@hotmail.com>
> 
>> We know that adult *Carnotaurus* did not have feathers over most of
>> their bodies.
> 
> I'm glad you specifed *adult* _Carnotaurus_.  I'm confident that the
> presence of feathers in at least some dinosaur taxa will one day be
> shown to have an ontogenetic component.

Hi Tim.  I wouldn't be _confident_ about this at all: I can't think of
a single living analogue, that is, an extant animal those young has
integument that is discarded in adults.  (And neither could Mike
Keesey when I raised the issue with him).

Mike points out that the big, naked animals we have now -- elephants,
rhinos, hippos -- all have young that are proportionally much closer
in size to the adults than a fresh-hatched _Carnotaurus_ would be to
its parents, so there would have been more _advantage_ for a baby
'taur having fluff than for a baby elephant.  But still, I'd be
hesitant about claiming to be _confident_ about something that we
don't see in broadly analogous (= "big" :-) animals today.

 _/|_    _______________________________________________________________
/o ) \/  Mike Taylor  <mike@indexdata.com>  http://www.miketaylor.org.uk
)_v__/\  "I try to take one day at a time, but sometimes several days
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