Re: Psittacosaurus Complexus

["Jaime A. Headden" <qilongia@yahoo.com>]

Garrison Hilliard (garrison@efn.org) wrote:

(I know this is tangential (but I think of interest in the endo-exothermic 
wars)... has any
exothermic animal ever had feathers?>

  I think you mean "ectothermic," but the answer is no. Only birds have 
feathers, as we define
them, among extant life-forms, and in the extinct realm only animals that 
apparently give direct
ancestry to birds (non-avian coelurosaurs) had anything like (up to including) 
feathers [seen in a
VERY bird-like dromaeosaurid, *Sinornithosaurus* -- see Xu, Zhang, and Prum, 
2001, early this year
in _Science_]. Animals like *Longisquama* may be touted as feather-bearing, but 
these would serve
no insulatory function in any sense, and are irrelevant to the discussion. 
*Cosesaurus* has
apparent "feathery" appendages, but these have not been studied in any useful 
detail that may
allow the ability to determine their function. We are left with the immediately 
describable. So,
in the present state of things, no, nothing besides birds and (as Martin has 
stated) a dinosaur
has feathers.


=====
Jaime A. Headden

  Little steps are often the hardest to take.  We are too used to making leaps 
in the face of adversity, that a simple skip is so hard to do.  We should all 
learn to walk soft, walk small, see the world around us rather than zoom by it.

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