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Re: Ptero fuzz distribution?




----- Original Message ----- From: "Jaime A. Headden" <qilongia@yahoo.com>
To: "jrc" <jrccea@bellsouth.net>
Cc: <dinosaur@usc.edu>
Sent: Thursday, July 27, 2006 5:10 AM
Subject: Re: Ptero fuzz distribution?



There is presently no evidence that I am
aware of that indicates that they are hair-like structures (structures with
function similar to that of hair, whatever their actual makeup).>

I would discount this, either, but I do not think they should be assumed to
be actinofibril remnants, either, as a null condition.

I agree.

There are two features,
and their nature should be independantly ascertained. However, in
*Beipiaopterus*, actinofibrils are present as well as the "hairs," so there are
independantly viable means of seeing which structure is which on the same patch
of dermis.

The following sentence is a speculation. It is possible that the structures are remnants of a disintegrating support structure for the actinofibrils, a mechanism for controlling or distributing the forces acting upon the actinofibrils between the actinofibrils. If so, the structures could be used to modulate and/or redirect the load paths in the membrane


Dermis where the 'fibrils are preserved as impressions, though,
don't seem to have preserved traces of the "hairs",

I agree and think that is significant.

yet even, integument seems
lacking in MANY Solnhofen fossils as well, to make those skin impression-based
fossils difficult to quantify.

I agree again.

Best wishes,
Jim