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Re: Feathers on Bloody Everything



Allan Edels wrote:
> 
> OK, Josh - I agree that there shouldn't be REAL FEATHERS on every dinosaur,
> however, I like with the idea that proto-feathers of some sort might be on
> every dinosaur - unless converted into real feathers or other structures
> (such as George suggests).
> 
>     Also, I had posted previously that Jack Horner once said that he thought
> that all dinos had downy feathers, which they lost as they grew older.  (He
> didn't specify ALL, but he implied it.  This was back around 1986 - over
> pizza and beer in New Jersey).
> 
        Sure, both of these points.  All I am saying is that we need to 
remember the key words in these two paragraphs, might and thought.  There 
is certainly the possibility that there are some sort of protofeathers on 
dinosaur integuments (alright, lets just go ahead and start calling them 
_Sinostructures_).  Hell, I very much like the idea that juveniles of 
many dinosaur clades might have integumentary structures that we might, 
at times of lesser judgement, call downy.  But, just because I like the 
idea doesn't mean that I am going to run around saying that it is so.  
That is all.  The evidence is still pretty weak for feather-stuff 
to be the default dinosaurian condition, no matter what the mighty Razor 
might say.  

        If we get a large "theropod" footprint in the Maastrichtian of 
Wyoming, let's say in the Lance Formation, for example, this footprint 
will probably be ascribed to if it is really large _T. rex_.  Why?  
Because, the overall theropod pedal structure is conservative enough
so that the track will look like a _T. rex_ foot could have made it and 
we don't have anything else from the fossil record that is large enough. 
So, it will be called a _T. rex_ track and a paper saying just that will 
probably come out.  The key point here is that "we don't have anything 
large enough in the fossil record."  We don't have anything in OUR fossil 
record.  The animal that actually made that track might in fact be 
there and we just haven't found it yet.  Whatever animal made 
_Saurexallopus_ hasn't shown up in the osteological record, but I am 
pretty sure it was there, at least long enough to walk in some wet sand. 

        I know it is hard to wait for data supporting our ideas to come 
out, especially in VP where collecting and prep takes so damn much time.  
There wasn't a lot of data to support the sauropods in the swamps ideas 
either, but look how that took off.  I guess I would just support going a 
little slower and not having to later correct four out of six things 
that I did.

        And I wasn't implying that I had come up with the hypothesis that 
juvenile dinosaurs might have a feather-like integument, just that the 
idea is really interesting now that there is actually enough evidence for us to 
actually entertain the thought.  It was a "wow, gee, isn't this cool" 
point, not a "listen to this new Idea that I have, aren't I so cool" point. 


-- 
__________________________
Josh Smith
University of Pennsylvania
Department of Earth and Environmental Science
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240 South 33rd Street
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smithjb@sas.upenn.edu