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Re: [GSP1954@aol.com: Re: dinosaur endothermy (long)]



On Wed, 11 Dec 1996, Terry D. Jones wrote:

> Currently, the only evidence that is functionallly linked to metabolism in
> extinct animals--including dinosaurs--is the presence or absence of nasal
> respiratory turbinates. 

        In Sinosauropteryx there are clearly visible dark patches of
hairlike insulatory structures, these run along the top of the neck,
back, and in broken clumps along the top and bottom of the
tail. However, reconstructions showing feathers only in these areas
are, I believe, incorrect. The reason why is because when I looked at
the photos I saw what I took to be the imprints of these structures on
the underside of the neck. The remains of the structures were gone,
but their imprint remains.
 Where did they go? Same place about half the tail insulation went: 
presumably, with the rest of the fossil. Remember, we're only dealing 
with _half_ the fossil, the part in Beijing. The counterpart slab will 
most likely answer our questions. 
        The other thing to remember is that feathers are preserved, 
apparently, only in the plane of the rock. You could see this in the 
longfeather birds preserved with arms and legs splayed out to  the sides 
and insulation around their sides. Note that the Nature article only 
notes insulation on Confuciusornis' legs. There is no reason to believe 
that Confuciusornis had insulation only on its legs, or that these birds 
had insulation only on their sides. If my eyes have not decieved me, the 
best conclusion is that insulation formed a dense coat over the entire 
animal. 
        Having a mostly bald animal (of this size) doesn't make a heck of 
a lot of sense, that's probably why I wasn't satisfied, even by such a 
spectacular specimen, and had to go looking for more insulation. 

        I understand peoples's reluctance to take other's words on such 
an incredible fossil, but believe me, they're there, it doesn't take an 
expert to see, and they're not like anything found on the skin of any 
modern reptile.