Re: [dinosaur] Bristle Scale As a Predecessor of Protofeather and Feather

[Tim Williams <tijawi@gmail.com>]

Ruben Safir <ruben@mrbrklyn.com> wrote:

> For some reason, I thought it was shown that feathers did not develope
> from scales, but were a new and separate anatomical feature.

Yes, that was impression too.  The weight of evidence supports the
hypothesis that scales and feathers are non-homologous.  From Prum &
Brush (2002): "Feathers are inherently tubular structures [i.e.,
feathers are NOT inherently planar, unlike scales]. The homology of
feathers and scales is weakly supported. Feathers are composed of a
suite of evolutionary novelties that evolved by the duplication,
hierarchical organization, interaction, dissociation, and
differentiation of morphological modules."