Re: [Combined answer: Feathered/scaly theropods: trying to make the point.]

["Zoe Heraklides" <z_heraklides@hotmail.com>]

"Jura" writes:
> So to rephrase: "All dinosaurs should be considered scaly by default, 
> unless
> there is evidence to the contrary."


I think the crux of the trouble here is that the opinions expressed here are 
very strong and forceful in their presentation. Yet, the opinions are based 
on little evidence - and based more or less (mostly "more") on Jura's 
assertions about dinosaurs and the Yixian localitie(s):
(1) all dinosaurs are the same where skin/integument is concerned, so we 
have no right to picture ANY dinosaurs were feathered unless we can prove 
they all were.
(2) all feathred dinosaurs are found in one tiny locality, which were 
susceptibel to some freaky fungal/dendritic phenomonen which look so much 
like feathers that paleontologists  havebeen fooled into thinking they are 
feathers.
(3) if some specimens shows preserved integument than they ALL should. In 
other words, Yixian mammals should show hair, Yixian ornithopods should show 
scutes/scales etc. (But preservation was differential according to the 
nature of the intgegument -  just like Solnhofen and Messel and Santana.)

Assertions 1,2,3 are incorrect. I am not going to accuse "Jura" of being 
uninformed in this discussion/debate. I would say that the strength of the 
opinions are not matched by Jura's grasp of the topic. To say that he has 
not aware of any Yixian birds beside Confuciusornis hints at this. There are 
at least 20 species of bird so far described, and some have been described 
in major easy-to-get journals (Science, Nature).

Also:
> > Check out
> > posts regarding dino metabolism, or theropod behaviour and see how often
> > maniraptor gets exapted to all theropods and occasionally, all dinosaurs.

"Exaptation" is an evolutionary term, coined by Gould (I think in the 
1980's). It means when an existing structure takes on a new (derived) 
function - and that new functiuon may replace the old one. I think your 
usage may not be right. Do you mean "extrapolate?"


Regards, Zoe



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