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On Wed, 29 Aug 2001 12:51:19 -0400 "Ray Stanford"
<dinotracker@earthlink.net> writes:

>     I appreciate Allan's (sic) extremely useful and informative post,
> am not
> aware that any in-depth analysis has been done of the hair-like 
> integument
> evidently fossilized on pterosaur body skin and perhaps (I seem to 
> recall)
> on their wing membranes that would conclusively determine that the
> structures are not hair, per se. 

Exactly. Nor has anyone ever shown that they ARE hair. Hair being the
keratin structures produced by the mammalian integument. The questionis
unanswered. As far as anyone knows only mammals produce hair in the sence
it contains an alpha-keratin, is an aunbranched filament, and has the
particular cellular structure.

Tje structures are only "hair-like". Please note the use of quotes. The
resemblance is only superficial at this point.

 There has been quite a bit of 
> opinion
> expressed on this in various places, but I have never seen any of it 
> (on
> either side) backed by convincing analysis.  If Alan or anyone else 
> could
> supply a pertinent reference and a synopsis of any such analysis and 
> its
> conclusions, it would be very much appreciated.

Absolutely. An at this point the structure and composition of these
structures is purely speculative; as is the function for that matter.

>     And while on that subject, has any particular dermal or 
> follicular
> patterning ever been reported in connection with growth of the 
> 'hair-like'
> integument of pterosaurs?  
I am not aware of any such report..



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