RE: SAUROPOD FEATHERS

["Ken Kinman" <kinman@hotmail.com>]

    I wholeheartedly agree with George, and I certainly hope Norell 
qualifies his statements by saying ornithischians and sauropodomorphs most 
likely had bristle-like protofeathers (and that they probably did not cover 
the whole body).  If not, he is going to give some people the false 
impression that they had vaned feathers like maniraptors and birds (i.e. 
birds sensu Kinman) and that they were first developed for body insulation 
(which I strongly doubt).  And it is certainly very disturbing to see 
Chinese scientists calling pterosaurs "feathered" if all they had were 
hairlike bristles.
    As for the sauropod embryos (or ornithischian embryos for that matter), 
I believe the first "bristles" would have been along the backbone and tail.  
If my "protofeathers evolved on the tail first" hypothesis is correct, they 
may well first  appear on the tail and then spread up the spine during 
ontogeny.
    I think this hypothesis may be supported by the bristle-tailed 
psittacosaur.  If tail bristles evolved first, then they may well have been 
the last to be lost as dinosaurs got bigger.    It is therefore no surprise 
to me that dinosaurs had considerable portions of the bodies lacking such 
protofeathers.  Even once exapted for brooding, only the posterior parts of 
the adult would *need* to be covered with brooding bristles.  Perhaps only 
in advanced coelurosaurs did they spread to arms and eventually become 
exapted for aerodynamic functions.
         ---- Cheers, Ken Kinman
P.S.  As for Longisquama, its paravaned parafeathers may well be homologous 
to protofeathers, but they are pretty clearly convergent on real vaned 
feathers found in Class Aves (sensu lato).
*****************************************
Dinogeorge wrote:
> For some time now I've suspected (and argued) that all dinosaurs had 
> feathers of some kind--perhaps not like those of modern birds but certainly 
> homologous keratinous dermal structures. These might occur quite far down 
> the archosaur clade and could well be homologous with pterosaur "hairs" and 
> even Longisquama "wings." Nice to know that there might actually be some 
> hard evidence for these.



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